Current Electricity · Physics · COMEDK

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MCQ (Single Correct Answer)

1
The wire made of Phosphor bronze is used as the suspension strip in the moving coil galvanometer, because:
COMEDK 2025 Afternoon Shift
2
Ten cells, each having internal resistance $1 \Omega$ and emf 1.5 V are connected in series. But unknowingly 3 cells are connected wrongly in series. The effective internal resistance and emf of the series combination are respectively:
COMEDK 2025 Afternoon Shift
3
A galvanometer of $50 \Omega$ resistance is converted into an ammeter using a shunt resistance of $10 \Omega$. If the same resistance is used to convert the same galvanometer in to a voltmeter, what would be the ratio of the resistance of the ammeter to the resistance of the voltmeter?
COMEDK 2025 Afternoon Shift
4
The resistance of the conductor is $\sqrt{3} \Omega$ the angle made by the V-I graph with the voltage axis is $\theta$
COMEDK 2025 Afternoon Shift
5
Across the 220 V source of internal resistance $20 \Omega$, how many lamps of $40 \mathrm{~W}, 100 \mathrm{~V}$ can be connected in parallel so that all the lamps may glow with full brightness.
COMEDK 2025 Afternoon Shift
6
Two wires A and B made of same material having length 10 cm and 40 cm respectively are connected in parallel to the same source of emf 10 V . What will be the ratio of the drift velocity of the electrons in the wire $A$ to the drift velocity in the wire $B$ ?
COMEDK 2025 Afternoon Shift
7
A student measures the terminal potential difference $V$ of a cell (emf $\varepsilon$ and internal resistance $r$ ) as a function of current I flowing through it, and draws V versus I graph. The slope and intercept of the graph respectively are
COMEDK 2025 Morning Shift
8
A galvanometer of resistance $50 \Omega$ is connected to a battery of 4 V along with a resistance of $3950 \Omega$ in series. A full-scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 10 divisions, the resistance in series should be equal to:
COMEDK 2025 Morning Shift
9
Two identical conductors of lengths 1 and 31 respectively are maintained at the same temperature. They are given potential differences in the ratio $1: 3$. The ratio of their drift velocities is
COMEDK 2025 Morning Shift
10
If voltage across a bulb rated $220 \mathrm{~V}, 50 \mathrm{~W}$ drops by $5 \%$ of its rated value, the percentage of the rated value by which the power would decrease is
COMEDK 2025 Morning Shift
11
The resistance of a wire is 5 ohm at $25^{\circ} \mathrm{C}$ and 7 ohm at $100^{\circ} \mathrm{C}$. The resistance of the wire at $0^{\circ} \mathrm{C}$ is
COMEDK 2025 Morning Shift
12

Three bulbs of $$40 \mathrm{~W}, 60 \mathrm{~W}$$, and $$100 \mathrm{~W}$$ are arranged in series with a $$220 \mathrm{~V}$$ source. The maximum light is obtained from

COMEDK 2024 Evening Shift
13

The resistance of a $$10 \mathrm{~m}$$ long wire is $$10 \Omega$$. Its length is increased by $$25 \%$$ by stretching the wire uniformly. The new resistance is

COMEDK 2024 Evening Shift
14

Four resistors, each of resistance R, are connected as shown in the figure below.

COMEDK 2024 Evening Shift Physics - Current Electricity Question 12 English

COMEDK 2024 Evening Shift
15

A voltmeter of resistance $$1000 \Omega .0 .5 \mathrm{~V} /$$ div is to be converted into a voltmeter to make it to read $$=1 \mathrm{~V} / \mathrm{div}$$. The value of high resistance to be connected in series with it is

COMEDK 2024 Evening Shift
16

The resistance of a wire at room temperature $$20^{\circ} \mathrm{C}$$ is found to be $$10 \Omega$$. If resistance of the wire increases by $$10 \%$$, then the temperature of the wire will be (The temperature coefficient of the material of the wire is $$0.002 /{ }^{\circ} \mathrm{C}$$)

COMEDK 2024 Afternoon Shift
17

The potential difference between the points $$\mathrm{P}$$ and $$\mathrm{Q}$$ of the arrangement shown in figure is

COMEDK 2024 Afternoon Shift Physics - Current Electricity Question 16 English

COMEDK 2024 Afternoon Shift
18

An electron starting from rest and moving with the velocity $$\mathrm{v}$$ through a potential difference $$\mathrm{V}$$ is shown by the graphs below. Identify the correct graph.

COMEDK 2024 Afternoon Shift
19

Two identical moving coil galvanometers have $$10 \Omega$$ resistance and full-scale deflection at $$2 \mu \mathrm{A}$$ current. One of them is converted into a voltmeter of range $$10 \mathrm{~mV}$$ and the other into an ammeter of range $$1 \mathrm{~mA}$$ using appropriate resistors. The ratio of resistance of the converted voltmeter to that of the ammeter is

COMEDK 2024 Afternoon Shift
20

A wire of uniform cross section and resistance 4 ohms is bent in the shape of square ABCD. Point A is connected to a point $$\mathrm{P}$$ on DC by a wire AP of resistance $$1 \mathrm{ohm}$$. When a potential difference is applied between $$\mathrm{A}$$ and $$\mathrm{C}$$, the points $$\mathrm{B}$$ and $$\mathrm{P}$$ are seen to be in same potential. What is the resistance of part $$\mathrm{DP}$$ ?

COMEDK 2024 Afternoon Shift Physics - Current Electricity Question 17 English

COMEDK 2024 Afternoon Shift
21

A storage battery of emf $$28.0 \mathrm{~V}$$ and internal resistance $$0.5 \Omega$$ is being charged by a $$140 \mathrm{~V}$$ dc supply using a series resistor of $$27.5 \Omega$$. The terminal voltage of the battery during charging is

COMEDK 2024 Afternoon Shift
22

The resistance of the galvanometer and shunt of an ammeter are $$90 \mathrm{~ohm}$$ and $$10 \mathrm{~ohm}$$ respectively, then the fraction of the main current passing through the galvanometer and the shut respectively are:

COMEDK 2024 Morning Shift
23

A $$500 \mathrm{~W}$$ heating unit is designed to operate on a $$400 \mathrm{~V}$$ line. If line voltage drops to $$160 \mathrm{~V}$$, the percentage drop in heat output will be:

COMEDK 2024 Morning Shift
24

A cell of emf E and internal resistance r is connected to two external resistances $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ and a perfect ammeter. The current in the circuit is measured in four different situations:

(a) without any external resistance in the circuit.

(b) with resistance $$\mathrm{R_1}$$ only

(c) with $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ in series combination.

(d) with $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ in parallel combination.

The currents measured in the four cases in ascending order are

COMEDK 2024 Morning Shift
25

The current through a conductor is '$$\mathrm{a}$$' when the temperature is $$0^{\circ} \mathrm{C}$$. It is '$$\mathrm{b}$$' when the temperature is $$100^{\circ} \mathrm{C}$$. The current through the conductor at $$220^{\circ} \mathrm{C}$$ is

COMEDK 2024 Morning Shift
26

On increasing the temperature of a conductor, its resistance increases because

COMEDK 2024 Morning Shift
27

A galvanometer having a resistance of $$8 \Omega$$ is shunted by a wire of resistance $$2 \Omega$$. If the total current is $$1 \mathrm{~A}$$, the part of it passing through the shunt will be

COMEDK 2023 Morning Shift
28

Two cells with the same emf $$E$$ and different internal resistances $$r_1$$ and $$r_2$$ are connected in series to an external resistance $$R$$. If the potential difference across the first cell is zero then value of $$R$$.

COMEDK 2023 Morning Shift
29

The current sensitivity of a galvanometer having 20 divisions is $$10 \mu \mathrm{A} /$$ div. If the resistance of the galvanometer is $$100 \Omega$$ then the value of the resistance to be used to convert this galvanometer in to an voltmeter to read up to $$1 \mathrm{~V}$$ is :

COMEDK 2023 Evening Shift
30

The electric flux from cube of side $$1 \mathrm{~m}$$ is '$$\Phi$$' When the side of the cube is made $$3 \mathrm{~m}$$ and the charge enclosed by the cube is made one third of the original value, then the flux from the bigger cube will be :

COMEDK 2023 Evening Shift
31

A resistor of wire $$24 \mathrm{~cm}$$ length and resistance $$8 \Omega$$ is stretched in to a uniform wire of $$48 \mathrm{~cm}$$ length, then the new resistance will be :

COMEDK 2023 Evening Shift
32

The SI unit of electrical conductivity is :

COMEDK 2023 Evening Shift
33

The current passing through the 100$$\Omega$$ resistor in the given electrical circuit is :

COMEDK 2023 Evening Shift Physics - Current Electricity Question 27 English

COMEDK 2023 Evening Shift
34

A battery is made of 12 cells having emf $$5 \mathrm{~V}$$ each. If three cells are unknowingly connected wrong, the resultant emf of the battery will be:

COMEDK 2023 Evening Shift
35

The current drawn by the primary coil of an ideal transformer, which steps up $$22 \mathrm{~V}$$ into $$220 \mathrm{~V}$$, to operate a device having a load resistance $$110 \Omega$$ is:

COMEDK 2023 Evening Shift
36

A galvanometer having a resistance of 4 $$\Omega$$ is shunted by a wire of resistance 2 $$\Omega$$. If the total current is 1.5 A, the current passing through shunt is

COMEDK 2022
37

A cell of emf 2 V is connected with a load of resistance 1.5 $$\Omega$$. The power delivered by the cell to the load is maximum, then power transferred to the load is

COMEDK 2022
38

The resistance of a wire is R ohm. If it is melted and stretched to n times its original length, its new resistance will be

COMEDK 2021
39

For the given electrical arrangement, what is the value of current I?

COMEDK 2021 Physics - Current Electricity Question 43 English

COMEDK 2021
40

If voltage $$V=(200\pm 8)V$$ and current $$I=(20\pm0.5)A$$, then the percentage error in resistance R is

COMEDK 2020
41

Point out the right statements about the validity of Kirchhoff’s junction rule,

COMEDK 2020
42

If $$P=Q=R=10\Omega$$ and $$S=20\Omega$$, then what resistance should be joined with S to balance the Wheatstone's network?

COMEDK 2020
43

To the potentiometer wire of length L and 10$$\Omega$$ resistance, a battery of emf 2.5 V and a resistance R are connected in series. If a potential difference of 1 V is balanced across L/2 length, the value of R in $$\Omega$$ will be

COMEDK 2020
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