Current Electricity · Physics · JEE Main

The effective resistance between $$A$$ and $$B$$, if resistance of each resistor is $$R$$, will be : ...

A galvanometer has a coil of resistance $$200 \Omega$$ with a full scale deflection at $$20 \mu \mathrm{A}$$. The value of resistance to be added to u...

The equivalent resistance between A and B is : ...

Water boils in an electric kettle in 20 minutes after being switched on. Using the same main supply, the length of the heating element should be _____...

In the given circuit, the terminal potential difference of the cell is : ...

The number of electrons flowing per second in the filament of a $$110 \mathrm{~W}$$ bulb operating at $$220 \mathrm{~V}$$ is : (Given $$\mathrm{e}=1.6...

The value of unknown resistance $$(x)$$ for which the potential difference between $$B$$ and $$D$$ will be zero in the arrangement shown, is : ...

The ratio of heat dissipated per second through the resistance $$5 \Omega$$ and $$10 \Omega$$ in the circuit given below is: ...

A galvanometer of resistance $$100 \Omega$$ when connected in series with $$400 \Omega$$ measures a voltage of upto $$10 \mathrm{~V}$$. The value of r...

In the given figure $$\mathrm{R}_1=10 \Omega, \mathrm{R}_2=8 \Omega, \mathrm{R}_3=4 \Omega$$ and $$\mathrm{R}_4=8 \Omega$$. Battery is ideal with emf ...

An electric bulb rated $$50 \mathrm{~W}-200 \mathrm{~V}$$ is connected across a $$100 \mathrm{~V}$$ supply. The power dissipation of the bulb is:...

To measure the internal resistance of a battery, potentiometer is used. For $$R=10 \Omega$$, the balance point is observed at $$l=500 \mathrm{~cm}$$ a...

In a metre-bridge when a resistance in the left gap is $2 \Omega$ and unknown resistance in the right gap, the balance length is found to be $40 \math...

In an ammeter, $5 \%$ of the main current passes through the galvanometer. If resistance of the galvanometer is $\mathrm{G}$, the resistance of ammete...

The reading in the ideal voltmeter $(\mathrm{V})$ shown in the given circuit diagram is : ...

A galvanometer has a resistance of $50 ~\Omega$ and it allows maximum current of $5 \mathrm{~mA}$. It can be converted into voltmeter to measure upto ...

By what percentage will the illumination of the lamp decrease if the current drops by 20%?

The resistance per centimeter of a meter bridge wire is $$r$$, with $$X \Omega$$ resistance in left gap. Balancing length from left end is at $$40 \ma...

Two conductors have the same resistances at $$0^{\circ} \mathrm{C}$$ but their temperature coefficients of resistance are $$\alpha_1$$ and $$\alpha_2$...

When a potential difference $$V$$ is applied across a wire of resistance $$R$$, it dissipates energy at a rate $$W$$. If the wire is cut into two halv...

A potential divider circuit is shown in figure. The output voltage V$$_0$$ is : ...

An electric toaster has resistance of $$60 \Omega$$ at room temperature $$\left(27^{\circ} \mathrm{C}\right)$$. The toaster is connected to a $$220 \m...

In the given circuit, the current in resistance R$$_3$$ is : ...

The deflection in moving coil galvanometer falls from 25 divisions to 5 division when a shunt of $$24 \Omega$$ is applied. The resistance of galvanome...

A galvanometer having coil resistance $$10 \Omega$$ shows a full scale deflection for a current of $$3 \mathrm{~mA}$$. For it to measure a current of ...

The electric current through a wire varies with time as $$I=I_0+\beta t$$, where $$I_0=20 \mathrm{~A}$$ and $$\beta=3 \mathrm{~A} / \mathrm{s}$$. The ...

Three voltmeters, all having different internal resistances are joined as shown in figure. When some potential difference is applied across $$A$$ and ...

A current of $$200 \mu \mathrm{A}$$ deflects the coil of a moving coil galvanometer through $$60^{\circ}$$. The current to cause deflection through $$...

Wheatstone bridge principle is used to measure the specific resistance $$\left(S_1\right)$$ of given wire, having length $$L$$, radius $$r$$. If $$X$$...

A wire of length $$10 \mathrm{~cm}$$ and radius $$\sqrt{7} \times 10^{-4} \mathrm{~m}$$ connected across the right gap of a meter bridge. When a resis...

A wire of resistance $$\mathrm{R}$$ and length $$\mathrm{L}$$ is cut into 5 equal parts. If these parts are joined parallely, then resultant resistanc...

For designing a voltmeter of range $50 \mathrm{~V}$ and an ammeter of range $10 \mathrm{~mA}$ using a galvanometer which has a coil of resistance $54 ...

Given below are two statements: Statement I : The equivalent resistance of resistors in a series combination is smaller than least resistance used in...

Different combination of 3 resistors of equal resistance $$\mathrm{R}$$ are shown in the figures. The increasing order for power dissipation is: ...

A wire of resistance $$160 ~\Omega$$ is melted and drawn in a wire of one-fourth of its length. The new resistance of the wire will be

The current flowing through R$$_2$$ is :...

Two identical heater filaments are connected first in parallel and then in series. At the same applied voltage, the ratio of heat produced in same tim...

The current sensitivity of moving coil galvanometer is increased by $$25 \%$$. This increase is achieved only by changing in the number of turns of co...

The equivalent resistance of the circuit shown below between points a and b is : ...

The equivalent resistance between A and B as shown in figure is: ...

Figure shows a part of an electric circuit. The potentials at points $$a, b$$ and $$c$$ are $$30 \mathrm{~V}, 12 \mathrm{~V}$$ and $$2 \mathrm{~V}$$ r...

A student is provided with a variable voltage source $$\mathrm{V}$$, a test resistor $$R_{T}=10 ~\Omega$$, two identical galvanometers $$G_{1}$$ and $...

Given below are two statements : One is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$. Assertion A : For mea...

Equivalent resistance between the adjacent corners of a regular n-sided polygon of uniform wire of resistance R would be :

The equivalent resistance between $$A$$ and $$B$$ of the network shown in figure; ...

The number of turns of the coil of a moving coil galvanometer is increased in order to increase current sensitivity by $50 \%$. The percentage change ...

The $\mathrm{H}$ amount of thermal energy is developed by a resistor in $10 \mathrm{~s}$ when a current of $4 \mathrm{~A}$ is passed through it. If th...

The drift velocity of electrons for a conductor connected in an electrical circuit is $$\mathrm{V}_{\mathrm{d}}$$. The conductor in now replaced by an...

The equivalent resistance between $A$ and $B$ is _________. ...

The charge flowing in a conductor changes with time as $$\mathrm{Q}(\mathrm{t})=\alpha \mathrm{t}-\beta \mathrm{t}^{2}+\gamma \mathrm{t}^{3}$$. Where ...

With the help of potentiometer, we can determine the value of emf of a given cell. The sensitivity of the potentiometer is (A) directly proportional t...

Ratio of thermal energy released in two resistors R and 3R connected in parallel in an electric circuit is :

The resistance of a wire is 5 $$\Omega$$. It's new resistance in ohm if stretched to 5 times of it's original length will be :

A uniform metallic wire carries a current 2 A, when 3.4 V battery is connected across it. The mass of uniform metallic wire is 8.92 $$\times$$ 10$$^{-...

A cell of emf 90 V is connected across series combination of two resistors each of 100$$\Omega$$ resistance. A voltmeter of resistance 400$$\Omega$$ i...

As shown in the figure, a network of resistors is connected to a battery of 24V with an internal resistance of 3 $$\Omega$$. The currents through the ...

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Alloys such as constantan and manga...

A $$1 \mathrm{~m}$$ long wire is broken into two unequal parts $$\mathrm{X}$$ and $$\mathrm{Y}$$. The $$\mathrm{X}$$ part of the wire is streched into...

Two metallic wires of identical dimensions are connected in series. If $$\sigma_{1}$$ and $$\sigma_{2}$$ are the conductivities of the these wires res...

Given below are two statements : Statement I : A uniform wire of resistance $$80 \,\Omega$$ is cut into four equal parts. These parts are now connecte...

A wire of resistance R1 is drawn out so that its length is increased by twice of its original length. The ratio of new resistance to original resistan...

(A) The drift velocity of electrons decreases with the increase in the temperature of conductor. (B) The drift velocity is inversely proportional to t...

Two sources of equal emfs are connected in series. This combination is connected to an external resistance R. The internal resistances of the two sour...

A battery of $$6 \mathrm{~V}$$ is connected to the circuit as shown below. The current I drawn from the battery is : ...

The current I in the given circuit will be : ...

A current of 15 mA flows in the circuit as shown in figure. The value of potential difference between the points A and B will be: ...

Which of the following physical quantities have the same dimensions?

An electric cable of copper has just one wire of radius 9 mm. Its resistance is 14 $$\Omega$$. If this single copper wire of the cable is replaced by ...

The combination of two identical cells, whether connected in series or parallel combination provides the same current through an external resistance o...

Resistance of the wire is measured as 2 $$\Omega$$ and 3 $$\Omega$$ at 10$$^\circ$$C and 30$$^\circ$$C respectively. Temperature co-efficient of resis...

A 72 $$\Omega$$ galvanometer is shunted by a resistance of 8 $$\Omega$$. The percentage of the total current which passes through the galvanometer is ...

The equivalent resistance between points A and B in the given network is : ...

An aluminium wire is stretched to make its length, 0.4% larger. The percentage change in resistance is :

Two cells of same emf but different internal resistances r1 and r2 are connected in series with a resistance R. The value of resistance R, for which t...

If n represents the actual number of deflections in a converted galvanometer of resistance G and shunt resistance S. Then the total current I when its...

A teacher in his physics laboratory allotted an experiment to determine the resistance (G) of a galvanometer. Students took the observations for $${1 ...

What will be the most suitable combination of three resistors A = 2$$\Omega$$, B = 4$$\Omega$$, C = 6$$\Omega$$ so that $$\left( {{{22} \over 3}} \rig...

Two identical cells each of emf 1.5 V are connected in parallel across a parallel combination of two resistors each of resistance 20 $$\Omega$$. A vol...

Due to cold weather a 1 m water pipe of cross-sectional area 1 cm2 is filled with ice at $$-$$10$$^\circ$$C. Resistive heating is used to melt the ice...

Two resistors R1 = (4 $$\pm$$ 0.8) $$\Omega$$ and R2 = (4 $$\pm$$ 0.4) $$\Omega$$ are connected in parallel. The equivalent resistance of their parall...

The equivalent resistance of the given circuit between the terminals A and B is :...

Consider a galvanometer shunted with 5$$\Omega$$ resistance and 2% of current passes through it. What is the resistance of the given galvanometer ?

The Colour coding on a carbon resistor is shown in the given figure. The resistance value of the given resistor is :...

For full scale deflection of total 50 divisions, 50 mV voltage is required in galvanometer. The resistance of galvanometer if its current sensitivity ...

Five identical cells each of internal resistance 1$$\Omega$$ and emf 5V are connected in series and in parallel with an external resistance 'R'. For w...

If you are provided a set of resistances 2$$\Omega$$, 4$$\Omega$$, 6$$\Omega$$ and 8$$\Omega$$. Connect these resistances so as to obtain an equivalen...

An electric bulb of 500 watt at 100 volt is used in a circuit having a 200 V supply. Calculate the resistance R to be connected in series with the bul...

In the given figure, the emf of the cell is 2.2 V and if internal resistance is 0.6$$\Omega$$. Calculate the power dissipated in the whole circuit :...

What equal length of an iron wire and a copper-nickel alloy wire, each of 2 mm diameter connected parallel to give an equivalent resistance of 3$$\Ome...

The resistance of a conductor at 15$$^\circ$$C is 16$$\Omega$$ and at 100$$^\circ$$C is 20$$\Omega$$. What will be the temperature coefficient of resi...

In the given figure, a battery of emf E is connected across a conductor PQ of length 'l' and different area of cross-sections having radii r1 and r2 (...

In the given potentiometer circuit arrangement, the balancing length AC is measured to be 250 cm. When the galvanometer connection is shifted from poi...

The given potentiometer has its wire of resistance 10$$\Omega$$. When the sliding contact is in the middle of the potentiometer wire, the potential dr...

In the given figure, there is a circuit of potentiometer of length AB = 10 m. The resistance per unit length is 0.1 $$\Omega$$ per cm. Across AB, a ba...

A Copper (Cu) rod of length 25 cm and cross-sectional area 3 mm2 is joined with a similar Aluminium (Al) rod as shown in figure. Find the resistance o...

A current of 5 A is passing through a non-linear magnesium wire of cross-section 0.04 m2. At every point the direction of current density is at an ang...

The value of current in the 6 $$\Omega$$ resistance is :...

In the experiment of Ohm's law, a potential difference of 5.0 V is applied across the end of a conductor of length 10.0 cm and diameter of 5.00 mm. Th...

Two cells of emf 2E and E with internal resistance r1 and r2 respectively are connected in series to an external resistor R (see figure). The value of...

The four arms of a Wheatstone bridge have resistances as shown in the figure. A galvanometer of 15$$\Omega$$ resistance is connected across BD. Calcul...

A current of 10A exists in a wire of cross-sectional area of 5 mm2 with a drift velocity of 2 $$\times$$ 10$$-$$3 ms$$-$$1. The number of free electro...

A resistor develops 500 J of thermal energy in 20 s when a current of 1.5A is passed through it. If the current is increased from 1.5A to 3A, what wil...

A conducting wire of length 'l', area of cross-section A and electric resistivity $$\rho$$ is connected between the terminals of a battery. A potentia...

A wire of 1$$\Omega$$ has a length of 1 m. It is stretched till its length increases by 25%. The percentage change in resistance to the nearest intege...

Five equal resistances are connected in a network as shown in figure. The net resistance between the points A and B is :...

A current through a wire depends on time as i = $$\alpha$$0t + $$\beta$$t2where $$\alpha$$0 = 20 A/s and $$\beta$$ = 8 As$$-$$2. Find the charge cross...

A cell E1 of emf 6V and internal resistance 2$$\Omega$$ is connected with another cell E2 of emf 4V and internal resistance 8$$\Omega$$ (as shown in t...

A circuit to verify Ohm's law uses ammeter and voltmeter in series or parallel connected correctly to the resistor. In the circuit :

In the figure shown, the current in the 10 V battery is close to : ...

In the circuit, given in the figure currents in different branches and value of one resistor are shown. Then potential at point B with respect to the ...

A galvanometer is used in laboratory for detecting the null point in electrical experiments. If, on passing a current of 6 mA it produces a deflection...

An electrical power line, having a total resistance of 2 $$\Omega $$, delivers 1 kW at 220 V. The efficiency of the transmission line is approximately...

A galvanometer of resistance G is converted into a voltmeter of range 0 – 1 V by connecting a resistance R1 in series with it. The additional resistan...

The value of current i1 flowing from A to C in the circuit diagram is : ...

A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within...

Two resistors 400$$\Omega $$ and 800$$\Omega $$ are connected in series across a 6 V battery. The potential difference measured by a voltmeter of 10 ...

Model a torch battery of length $$l$$ to be made up of a thin cylindrical bar of radius ‘a’ and a concentric thin cylindrical shell of radius ‘b’ fill...

A potentiometer wire PQ of 1 m length is connected to a standard cell E1. Another cell E2 of emf 1.02 V is connected with a resistance ‘r’ and switch ...

Consider four conducting materials copper, tungsten, mercury and aluminium with resistivity $$\rho $$C, $$\rho $$T, $$\rho $$M and $$\rho $$A respecti...

In the given circuit diagram, a wire is joining points B and D. The current in this wire is : ...

A galvanometer having a coil resistance 100 $$\Omega $$ gives a full scale deflection when a current of 1 mA is passed through it. What is the value o...

The length of a potentiometer wire is 1200 cm and it carries a current of 60 mA. For a cell of emf 5V and internal resistance of 20$$\Omega $$, the nu...

In a building there are 15 bulbs of 45 W, 15 bulbs of 100 W, 15 small fans of 10 W and 2 heaters of 1 kW. The voltage of electric main is 220 V. The m...

The current I1 (in A) flowing through 1 $$\Omega $$ resistor in the following circuit is : ...

A moving coil galvanometer, having a resistance G, produces full scale deflection when a current Ig flows through it. This galvanometer can be convert...

The resistive network shown below is connected to a D.C. source of 16 V. The power consumed by the network is 4 Watt. The value of R is: ...

A galvanometer of resistance 100 $$\Omega $$ has 50 divisions on its scale and has sensitivitv of 20 $$\mu $$A/division. It is to be converted to a vo...

To verify Ohm's law, a student connects the voltmeter across the battery as, shown in the figure. The measured voltage is plotted as a function of the...

Space between two concentric conducting spheres of radii a and b (b > a) is filled with a medium of resistivity $$\rho $$. The resistance between t...

A current of 5 A passes through a copper conductor (resistivity = 1.7 × 10–8 $$\Omega $$m) of radius of cross-section 5 mm. Find the mobility of the c...

In a meter bridge experiment, the circuit diagram and the corresponding observation table are shown in figure .tg {border-collapse:collapse;border-...

In an experiment, the resistance of a material is plotted as a function of temperature (in some range). As shown in the figure, it is a straight line....

A moving coil galvanometer allows a full scale current of 10–4 A. A series resistance of 2 M$$\Omega $$ is required to convert the above galvanometer ...

In the given circuit, an ideal voltmeter connected across the 10$$\Omega $$ resistance reads 2V. The internal resistance r, of each cell is: ...

A metal wire of resistance 3 $$\Omega $$ is elongated to make a uniform wire of double its previous length. This new wire is now bent and the ends jo...

The resistance of a galvanometer is 50 ohm and the maximum current which can be passed through it is 0.002 A. What resistance must be connected to it ...

In a conductor, if the number of conduction electrons per unit volume is 8.5 × 1028 m–3 and mean free time is 25ƒs (femto second), it's approximate re...

A wire of resistance R is bent to form a square ABCD as shown in the figure. The effective resistance between E and C is : (E is mid-point of arm CD) ...

A moving coil galvanometer has resistance 50$$\Omega $$ and it indicates full deflection at 4mA current. A voltmeter is made using this galvanometer a...

In the circuit shown, a four-wire potentiometer is made of a 400 cm long wire, which extends between A and B. The resistance per unit length of the po...

A cell of internal resistance r drives current through an external resistance R. The power delivered by the cell to the external resistance will be ma...

In the figure shown, what is the current (in Ampere) drawn from the battery ? You are given: R1 = 15$$\Omega $$, R2 = 10 $$\Omega $$, R3 = 20 $$\Omega...

A 200 $$\Omega $$ resistor has a certain color code. If one replaces the red color by green in the code, the new resistance will be :

For the circuit shown, with R1 = 1.0W, R2 = 2.0 W, E1 = 2 V and E2 = E3 = 4 V, the potential difference between the points 'a' and 'b' is approximatel...

In the given circuit diagram, the currents, I1 = – 0.3 A, I4 = 0.8 A and I5 = 0.4 A, are flowing as shown. The currents I2, I3 and I6, respectively, ...

A galvanometer, whose resistance is 50 ohm, has 25 divisions in it. When a current of 4 $$ \times $$ 10–4 A passes through it, its needle ( pointer) d...

The galvanometer deflection, when key K1 is closed but K2 is open, equals $$\theta $$0 (see figure). On closing K2 also and adjusting R2 to 5$$\Omega ...

Two electric bulbs, rated at (25 W, 220 V) and (100 W, 220 V), are connected in series across a 220 V voltage source. If the 25 W and 100 W bulbs draw...

An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and esistance 5 $$\Omega $$....

In a meter bridge, the wire of length 1 m has a non-uniform cross-section such that, the variation $${{dR} \over {d\ell }}$$ of its resistance R with ...

A galvanometer having a resistance of 20 $$\Omega $$ and 30 divisions on both sides has figure of merit 0.005 ampere/division. The resistance that sho...

In the circuit shown, the potential difference between A and B is : ...

In the experimental set up of metre bridge shown in the figure, the null point is obtained at a distance of 40 cm from A. If a 10 $$\Omega $$ resistor...

Two equal resistances when connected in series to a battery, consume electric power of 60 W. If these resistances are now connected in parallel combin...

The resistance of the meter bridge AB in given figure is 4 $$\Omega $$. With a cell of emf $$\varepsilon $$ = 0.5 V and rheostat resistance Rh = 2 $$\...

In a Wheatstone bridge(see fig.), Resistances P and Q are approximately equal. When R = 400 $$\Omega $$, the bridge is balanced. On interchanging P an...

A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is con...

The actual value of resistance R, shown in the figure is 30$$\Omega $$. This is measuered in an experiment as shown using the standard formula R = $${...

The Wheatstone bridge shown in figure, here, gets balanced when the carbon resistor used as R1 has the colour code (Orange, Red, Brown). The resistors...

A uniform metallic wire has a resistance of 18 $$\Omega $$ and is bent into an equilateral triangle. Then, the resistance between any two vertices of ...

A 2 W carbon resistor is color coded with green, black, red and brown respectively. The maximum current which can be passed through this resistor is -

In the given circuit the cells have zero internal resistance. The currents (in Amperes) passing through resistance R1 and R2 respectively, are - ...

A potentiometer wire AB having length L and resistance 12 r is joined to a cell D of emf $$\varepsilon $$ and internal resistance r. A cell C having e...

In the given circuit the the internal resistance of the 18 V cell is negligible. If R1 = 400 $$\Omega $$, R3 = 100 $$\Omega $$ and R4 = 500 $$\Omega $...

A carbon resistance has a following colour code. What is the value of the resistance ? ...

When the switch S, in the circuit shown, is closed, then the value of current i will be : ...

A resistance is shown in the figure. Its value and tolerance are given respectively by : ...

Drift speed of electrons, when 1.5 A of current flows in a copper wire of cross section 5 mm2, is $$\upsilon $$. If the electron density in copper is ...

A heating element has a resistance of 100 $$\Omega $$ at room temperature. When it is connected to a supply of 220 V, a steady current of 2 A passes ...

A galvanometer with its coil resistance 25 $$\Omega $$ requires a current of 1 mA for its full deflection. In order to construct an ammeter to read up...

In a circuit for finding the resistance of a galvanometer by half deflection method, a 6 V battery and a high resistance of 11 k$$\Omega $$ are used...

Two batteries with e.m.f 12 V and 13 V are connected in parallel across a load resistor of 10 $$\Omega $$. The internal resistances of the two batteri...

On interchanging the resistances, the balance point of a meter bridge shifts to the left by 10 cm. The resistance of their series combination is 1 k$$...

In a potentiometer experiment, it is found that no current passes through the galvanometer when the terminals of the cell are connected across 52 cm o...

A copper rod of cross-sectional area A carries a uniform current I through it. At temperature T, if the volume charge density of the rod is $$\rho $$,...

A constant voltages is applied between two ends of a metallic wire. If the length is halved and the radius of the wire is doubled, the rate of heat de...

In a meter bridge, as shown in the figure, it is given that resistance $$Y = 12.5\,\,\Omega $$ and that the balance is obtained at a distance $$39.5...

In the given circuit all resistances are of value $$R$$ $$ohm$$ each. The equivalent resistance between $$A$$ and $$B$$ is : ...

The figure shows three circuits I, II and III which are connected to a 3V battery. If the powers dissipated by the configurations I, II and III are P1...

In a meter bridge experiment resistances are connected as shown in the figure. Initially resistance P = 4 $$\Omega $$ and the neutral point N is at 60...

A uniform wire of length 1 and radius r has a resistance of 100 $$\Omega $$. It is recast into a wire of radius $${r \over 2}.$$ The resistance of n...

A 9 V battery with internal resistance of 0.5 $$\Omega $$ is connected across an infinite network as shown in the figure. All ammeters A1, A2, 3 ...

A potentiometer PQ is set up to compare two resistances as shown in the figure. The ammeter A in the circuit reads 1.0 A when two way key K3 is open....

Which of the following statements is false?

In the given circuit, the current in each resistance is: ...

When a current of 5 mA is passed through a galvanometer having a coil of resistance 15$$\Omega $$, it shows full scale deflection. The value of the re...

A galvanometer has a 50 division scale. Battery has no internal resistance. It is found that there is deflection of 40 divisions when R = 2400 $$\Omeg...

The resistance of an electrical toaster has a temperature dependence given by R(T) = R0 [1 + $$\alpha $$(T − T0)] in its range of operation. At T0 = 3...

In the circuit shown, the resistance r is a variable resistance. If for r = fR, the heat generation in r is maximum then the value of f is : ...

A 50 $$\Omega $$ resistance is connected to a battery of 5 V. A galvanometer of resistance 100 $$\Omega $$ is to be used as an ammeter to measure curr...

A galvanometer having a coil resistance of $$100\,\Omega $$ gives a full scale deflection, when a currect of $$1$$ $$mA$$ is passed through it. The va...

In the circuit shown, the current in the $$1\Omega $$ resistor is : ...

When $$5V$$ potential difference is applied across a wire of length $$0.1$$ $$m,$$ the drift speed of electrons is $$2.5 \times {10^{ - 4}}\,\,m{s^{ -...

In a large building, three are $$15$$ bulbs of $$40$$ $$W$$, $$5$$ bulbs of $$100$$ $$W$$, $$5$$ fans of $$80$$ $$W$$ and $$1$$ heater of $$1$$ $$kW.$...

The supply voltage to room is $$120V.$$ The resistance of the lead wires is $$6\Omega $$. A $$60$$ $$W$$ bulb is already switched on. What is the decr...

This questions has Statement - $${\rm I}$$ and Statement - $${\rm I}$$$${\rm I}$$. Of the four choices given after the Statements, choose the one that...

Two electric bulbs marked $$25W$$ $$-$$ $$220$$ $$V$$ and $$100W$$ $$-$$ $$220V$$ are connected in series to a $$440$$ $$V$$ supply. Which of the bulb...

If a wire is stretched to make it $$0.1\% $$ longer, its resistance will:

Two conductors have the same resistance at $${0^ \circ }C$$ but their temperature coefficients of resistance are $${\alpha _1}$$ and $${\alpha _2}.$$ ...

Shown in the figure below is a meter-bridge set up with null deflection in the galvanometer. The value of the unknown resister $$R$$ is ...

Consider a block of conducting material of resistivity $$'\rho '$$ shown in the figure. Current $$'I'$$ enters at $$'A'$$ and leaves from $$'D'$$. We ...

Consider a block of conducting material of resistivity $$'\rho '$$ shown in the figure. Current $$'I'$$ enters at $$'A'$$ and leaves from $$'D'$$. We ...

A $$5V$$ battery with internal resistance $$2\Omega $$ and a $$2V$$ battery with internal resistance $$1\Omega $$ are connected to a $$10\Omega $$ res...

The resistance of a wire is $$5$$ ohm at $${50^ \circ }C$$ and $$6$$ ohm at $${100^ \circ }C.$$ The resistance of the wire at $${0^ \circ }C$$ will be...

A thermocouple is made from two metals, Antimony and Bismuth. If one junction of the couple is kept hot and the other is kept cold, then, an electric ...

An electric bulb is rated $$220$$ volt - $$100$$ watt. The power consumed by it when operated on $$110$$ volt will be

In a Wheatstone's bridge, three resistance $$P, Q$$ and $$R$$ connected in the three arms and the fourth arm is formed by two resistances $${S_1}$$ an...

The resistance of bulb filmanet is $$100\Omega $$ at a temperature of $${100^ \circ }C.$$ If its temperature coefficient of resistance be $$0.005$$ pe...

The current $${\rm I}$$ drawn from the $$5$$ volt source will be ...

A moving coil galvanometer has $$150$$ equal divisions. Its current sensitivity is $$10$$- divisions per milliampere and voltage sensitivity is $$2$$ ...

An energy source will supply a constant current into the load if its internal resistance is

In a potentiometer experiment the balancing with a cell is at length $$240$$ $$cm.$$ On shunting the cell with a resistance of $$2\Omega ,$$ the bala...

The resistance of hot tungsten filament is about $$10$$ times the cold resistance. What will be resistance of $$100$$ $$W$$ and $$200$$ $$V$$ lamp whe...

Two voltmeters, one of copper and another of silver, are joined in parallel. When a total charge $$q$$ flows through the voltmeters, equal amount of m...

Two sources of equal $$emf$$ are connected to an external resistance $$R.$$ The internal resistance of the two sources are $${R_1}$$ and $${R_2}\lef...

In the circuit, the galvanometer $$G$$ shows zero deflection. If the batteries $$A$$ and $$B$$ have negligible internal resistance, the value of the r...

A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

An electric current is passed through a circuit containing two wires of the same material, connected in parallel. If the lengths and radii are in the ...

The resistance of the series combination of two resistances is $$S.$$ When they are jointed in parallel the total resistance is $$P.$$ If $$S = nP$$ t...

The total current supplied to the circuit by the battery is ...

Thermistors are usually made of

In a meter bridge experiment null point is obtained at $$20$$ $$cm$$, from one end of the wire when resistance $$X$$ is balanced against another resi...

The thermo $$emf$$ of a thermocouple varies with temperature $$\theta $$ of the hot junction as $$E = a\theta + b{\theta ^2}$$ in volts where the ra...

The electrochemical equivalent of a metal is $${3.35109^{ - 7}}$$ $$kg$$ per Coulomb. The mass of the metal liberated at the cathode when a $$3A$$ cur...

The Kirchhoff's first law $$\left( {\sum i = 0} \right)$$ and second law $$\left( {\sum iR = \sum E} \right),$$ where the symbols have their usual mea...

A material $$'B'$$ has twice the specific resistance of $$'A'.$$ A circular wire made of $$'B'$$ has twice the diameter of a wire made of $$'A'$$. The...

The length of a given cylindrical wire is increased by $$100\% $$. Due to the consequent decrease in diameter the change in the resistance of the wire...

A $$220$$ volt, $$1000$$ watt bulb is connected across a $$110$$ $$volt$$ mains supply. The power consumed will be

A $$3$$ volt battery with negligible internal resistance is connected in a circuit as shown in the figure. The current $${\rm I}$$, in the circuit wil...

The nagative $$Zn$$ pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by $$0.13g$$ in $$30$$ minutes. If the ele...

The thermo $$e.m.f.$$ of a thermo -couple is $$25$$ $$\mu V/{}^ \circ C$$ at room temperature. A galvanometer of $$40$$ $$ohm$$ resistance, capable of...

The length of a wire of a potentiometer is $$100$$ $$cm$$, and the $$e.$$ $$m.$$ $$f.$$ of its standard cell is $$E$$ volt. It is employed to measure ...

An ammeter reads upto $$1$$ ampere. Its internal resistance is $$0.81$$ $$ohm$$. To increase the range to $$10$$ $$A$$ the value of the required shunt...

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

A wire when connected to $$220$$ $$V$$ mains supply has power dissipation $${P_1}.$$ Now the wire is cut into two equal pieces which are connected in ...

If in the circuit, power dissipation is $$150W,$$ then $$R$$ is ...

The mass of product liberated on anode in an electrochemical cell depends on (where $$t$$ is the time period for which the current is passed).

If $${\theta _1},$$ is the inversion temperature, $${\theta _n}$$ is the neutral temperature, $${\theta _c}$$ is the temperature of the cold junction...

To determine the resistance (R) of a wire, a circuit is designed below. The $$V$$-$$I$$ characteristic curve for this circuit is plotted for the voltm...

At room temperature $$(27^{\circ} \mathrm{C})$$, the resistance of a heating element is $$50 \Omega$$. The temperature coefficient of the material is ...

The current flowing through the $$1 \Omega$$ resistor is $$\frac{n}{10}$$ A. The value of $$n$$ is _______. ...

A heater is designed to operate with a power of $$1000 \mathrm{~W}$$ in a $$100 \mathrm{~V}$$ line. It is connected in combination with a resistance o...

Resistance of a wire at $$0^{\circ} \mathrm{C}, 100^{\circ} \mathrm{C}$$ and $$t^{\circ} \mathrm{C}$$ is found to be $$10 \Omega, 10.2 \Omega$$ and $$...

In the given figure an ammeter A consists of a $$240 \Omega$$ coil connected in parallel to a $$10 \Omega$$ shunt. The reading of the ammeter is _____...

A wire of resistance $$R$$ and radius $$r$$ is stretched till its radius became $$r / 2$$. If new resistance of the stretched wire is $$x ~R$$, then v...

A wire of resistance $$20 \Omega$$ is divided into 10 equal parts, resulting pairs. A combination of two parts are connected in parallel and so on. No...

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of $$1 / \theta$$ vs the resistance (R) of the resistan...

Two wires $$A$$ and $$B$$ are made up of the same material and have the same mass. Wire $$A$$ has radius of $$2.0 \mathrm{~mm}$$ and wire $$B$$ has ra...

Twelve wires each having resistance $$2 \Omega$$ are joined to form a cube. A battery of $$6 \mathrm{~V}$$ emf is joined across point $$a$$ and $$c$$....

The current in a conductor is expressed as $I=3 t^2+4 t^3$, where $I$ is in Ampere and $t$ is in second. The amount of electric charge that flows thro...

In the following circuit, the battery has an emf of $$2 \mathrm{~V}$$ and an internal resistance of $$\frac{2}{3} \Omega$$. The power consumption in t...

Equivalent resistance of the following network is __________ $$\Omega$$. ...

Two resistance of $$100 \Omega$$ and $$200 \Omega$$ are connected in series with a battery of $$4 \mathrm{~V}$$ and negligible internal resistance. A ...

Two cells are connected in opposition as shown. Cell $$\mathrm{E}_1$$ is of $$8 \mathrm{~V}$$ emf and $$2 \Omega$$ internal resistance; the cell $$\ma...

In the given circuit, the current flowing through the resistance $$20 \Omega$$ is $$0.3 \mathrm{~A}$$, while the ammeter reads $$0.9 \mathrm{~A}$$. Th...

A network of four resistances is connected to $9 \mathrm{~V}$ battery, as shown in figure. The magnitude of voltage difference between the points $\ma...

When a resistance of $$5 ~\Omega$$ is shunted with a moving coil galvanometer, it shows a full scale deflection for a current of $$250 \mathrm{~mA}$$,...

A potential $$\mathrm{V}_{0}$$ is applied across a uniform wire of resistance $$R$$. The power dissipation is $$P_{1}$$. The wire is then cut into two...

The current flowing through a conductor connected across a source is $$2 \mathrm{~A}$$ and 1.2 $$\mathrm{A}$$ at $$0^{\circ} \mathrm{C}$$ and $$100^{\...

Two identical cells each of emf $$1.5 \mathrm{~V}$$ are connected in series across a $$10 ~\Omega$$ resistance. An ideal voltmeter connected across $$...

In the circuit diagram shown in figure given below, the current flowing through resistance $$3 ~\Omega$$ is $$\frac{x}{3} A$$. The value of $$x$$ is _...

A rectangular parallelopiped is measured as $$1 \mathrm{~cm} \times 1 \mathrm{~cm} \times 100 \mathrm{~cm}$$. If its specific resistance is $$3 \times...

10 resistors each of resistance 10 $$\Omega$$ can be connected in such as to get maximum and minimum equivalent resistance. The ratio of maximum and m...

The number density of free electrons in copper is nearly $$8 \times 10^{28} \mathrm{~m}^{-3}$$. A copper wire has its area of cross section $$=2 \time...

A current of $$2 \mathrm{~A}$$ flows through a wire of cross-sectional area $$25.0 \mathrm{~mm}^{2}$$. The number of free electrons in a cubic meter a...

As shown in the figure, the voltmeter reads $$2 \mathrm{~V}$$ across $$5 ~\Omega$$ resistor. The resistance of the voltmeter is _________ $$\Omega$$. ...

The length of a metallic wire is increased by $$20 \%$$ and its area of cross section is reduced by $$4 \%$$. The percentage change in resistance of t...

In the given circuit, the value of $$\left| {{{{\mathrm{I_1}} + {\mathrm{I_3}}} \over {{\mathrm{I_2}}}}} \right|$$ is _____________ ...

In an experiment to find emf of a cell using potentiometer, the length of null point for a cell of emf $$1.5 \mathrm{~V}$$ is found to be $$60 \mathrm...

Two identical cells, when connected either in parallel or in series gives same current in an external resistance $$5 ~\Omega$$. The internal resistanc...

If the potential difference between $\mathrm{B}$ and $\mathrm{D}$ is zero, the value of $x$ is $\frac{1}{n} \Omega$. The value of $n$ is __________. ...

In the following circuit, the magnitude of current I1, is ___________ A. ...

A null point is found at 200 cm in potentiometer when cell in secondary circuit is shunted by 5$$\Omega$$. When a resistance of 15$$\Omega$$ is used f...

When two resistance $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ connected in series and introduced into the left gap of a meter bridge and a resistance of 1...

In a metre bridge experiment the balance point is obtained if the gaps are closed by 2$$\Omega$$ and 3$$\Omega$$. A shunt of X $$\Omega$$ is added to ...

Two cells are connected between points A and B as shown. Cell 1 has emf of 12 V and internal resistance of 3$$\Omega$$. Cell 2 has emf of 6V and inter...

In the given circuit, the equivalent resistance between the terminal A and B is __________ $$\Omega$$. ...

If a copper wire is stretched to increase its length by 20%. The percentage increase in resistance of the wire is __________%.

A hollow cylindrical conductor has length of 3.14 m, while its inner and outer diameters are 4 mm and 8 mm respectively. The resistance of the conduct...

The current I flowing through the given circuit will be __________A. ...

An electrical bulb rated 220 V, 100 W, is connected in series with another bulb rated 220 V, 60 W. If the voltage across combination is 220 V, the pow...

As shown in the figure, a potentiometer wire of resistance $$20 \,\Omega$$ and length $$300 \mathrm{~cm}$$ is connected with resistance box (R.B.) and...

In the given figure of meter bridge experiment, the balancing length AC corresponding to null deflection of the galvanometer is $$40 \mathrm{~cm}$$. T...

In a meter bridge experiment, for measuring unknown resistance 'S', the null point is obtained at a distance $$30 \mathrm{~cm}$$ from the left side as...

A $$1 \mathrm{~m}$$ long copper wire carries a current of $$1 \mathrm{~A}$$. If the cross section of the wire is $$2.0 \mathrm{~mm}^{2}$$ and the resi...

A potentiometer wire of length $$300 \mathrm{~cm}$$ is connected in series with a resistance 780 $$\Omega$$ and a standard cell of emf $$4 \mathrm{V}$...

Resistances are connected in a meter bridge circuit as shown in the figure. The balancing length $$l_{1}$$ is $$40 \mathrm{~cm}$$. Now an unknown resi...

In a potentiometer arrangement, a cell of emf 1.20 V gives a balance point at 36 cm length of wire. This cell is now replaced by another cell of emf 1...

In the given figure, the value of Vo will be _____________ V. ...

Eight copper wire of length $$l$$ and diameter $$d$$ are joined in parallel to form a single composite conductor of resistance $$R$$. If a single copp...

The circuit diagram of potentiometer used to measure the internal resistance of a cell (E) is shown in figure. The key 'K' is kept closed so as to sen...

Two resistors are connected in series across a battery as shown in figure. If a voltmeter of resistance 2000 $$\Omega$$ is used to measure the potenti...

The variation of applied potential and current flowing through a given wire is shown in figure. The length of wire is 31.4 cm. The diameter of wire is...

For the network shown below, the value of VB $$-$$ VA is ____________ V. ...

All resistances in figure are 1 $$\Omega$$ each. The value of current 'I' is $${a \over 5}$$ A. The value of a is _________. ...

A meter bridge setup is shown in the figure. It is used to determine an unknown resistance R using a given resistor of 15 $$\Omega$$. The galvanometer...

Current measured by the ammeter (A) in the reported circuit when no current flows through 10 $$\Omega$$ resistance, will be ________________ A. ...

The current density in a cylindrical wire of radius r = 4.0 mm is 1.0 $$\times$$ 106 A/m2. The current through the outer portion of the wire between r...

In the given circuit 'a' is an arbitrary constant. The value of m for which the equivalent circuit resistance is minimum, will be $$\sqrt {{x \over 2}...

A cell, shunted by a 8 $$\Omega$$ resistance, is balanced across a potentiometer wire of length 3 m. The balancing length is 2 m when the cell is shun...

The current density in a cylindrical wire of radius 4 mm is 4 $$\times$$ 106 Am$$-$$2. The current through the outer portion of the wire between radia...

The length of a given cylindrical wire is increased to double of its original length. The percentage increase in the resistance of the wire will be __...

A resistor develops 300 J of thermal energy in 15 s, when a current of 2 A is passed through it. If the current increases to 3 A, the energy developed...

The total current supplied to the circuit as shown in figure by the 5 V battery is ____________ A. ...

A potentiometer wire of length 10 m and resistance 20 $$\Omega$$ is connected in series with a 25 V battery and an external resistance 30 $$\Omega$$. ...

In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If t...

A uniform heating wire of resistance 36$$\Omega$$ is connected across a potential difference of 240 V. The wire is then cut into half and potential di...

A resistor dissipates 192 J of energy in 1s when a current of 4A is passed through it. Now, when the current is doubled, the amount of thermal energy ...

A square shaped wire with resistance of each side 3$$\Omega$$ is bent to form a complete circle. The resistance between two diametrically opposite poi...

The voltage drop across 15$$\Omega$$ resistance in the given figure will be ______________ V....

The ratio of the equivalent resistance of the network (shown in figure) between the points a and b when switch is open and switch is closed is x : 8. ...

First, a set of n equal resistors of 10 $$\Omega$$ each are connected in series to a battery of emf 20V and internal resistance 10$$\Omega$$. A curren...

For the circuit shown, the value of current at time t = 3.2 s will be _________ A.[Voltage distribution V(t) is shown by Fig. (1) and the circuit is s...

A 16 $$\Omega$$ wire is bend to form a square loop. A 9V supply having internal resistance of 1$$\Omega$$ is connected across one of its sides. The po...

An electric bulb rated as 200 W at 100 V is used in a circuit having 200 V supply. The resistance 'R' that must be put in series with the bulb so that...

In an electric circuit, a cell of certain emf provides a potential difference of 1.25 V across a load resistance of 5$$\Omega$$. However, it provides ...

In the given figure switches S1 and S2 are in open condition. The resistance across ab when the switches S1 and S2 are closed is _____________ $$\Omeg...

Two wires of same length and thickness having specific resistances 6$$\Omega$$ cm and 3$$\Omega$$ cm respectively are connected in parallel. The effec...

Consider a 72 cm long wire AB as shown in the figure. The galvanometer jockey is placed at P on AB at a distance x cm from A. The galvanometer shows z...

The voltage across the 10$$\Omega$$ resistor in the given circuit is x volt.The value of 'x' to the nearest integer is _________....

The equivalent resistance of series combination of two resistors is 's'. When they are connected in parallel, the equivalent resistance is 'p'. If s =...

The energy dissipated by a resistor is 10 mJ in 1 s when an electric current of 2 mA flows through it. The resistance is ___________$$\Omega$$. (Round...

In the figure given, the electric current flowing through the 5 k$$\Omega$$ resistor is 'x' mA.The value of x to the nearest integer is ____________....

In an electrical circuit, a battery is connected to pass 20C of charge through it in a certain given time. The potential difference between two plates...

A current of 6A enters one corner P of an equilateral triangle PQR having 3 wires of resistance 2$$\Omega$$ each and leaves by the corner R. The curre...

In the given circuit of potentiometer, the potential difference E across AB (10 m length) is larger than E1 and E2 as well. For key K1 (closed), the j...

A cylindrical wire of radius 0.5 mm and conductivity 5 $$\times$$ 107 S/m is subjected to an electric field of 10 mV/m. The expected value of current ...

Four resistances 40 $$\Omega $$, 60 $$\Omega $$, 90 $$\Omega $$ and 110 $$\Omega $$ make the arms of a quadrilateral ABCD. Across AC is a battery of e...

In a meter bridge experiment S is a standard resistance. R is a resistance wire. It is found that balancing length is $$l$$ = 25 cm. If R is replaced ...

The series combination of two batteries, both of the same emf 10 V, but different internal resistance of 20$$\Omega $$ and 5$$\Omega $$, is connected ...

Four resistances of 15$$\Omega $$, 12$$\Omega $$, 4$$\Omega $$ and 10$$\Omega $$ respectively in cyclic order to form Wheatstone's network. The resist...

The balancing length for a cell is 560 cm in a potentiometer experiment. When an external resistance of 10 $$\Omega $$ is connected in parallel to the...