Alternating Current · Physics · NEET

In the circuit shown below, the inductance $$L$$ is connected to an ac source. The current flowing in the circuit is $$I=I_0 \sin \omega t$$. The volt...

A step up transformer is connected to an ac mains supply of $$220 \mathrm{~V}$$ to operate at $$11000 \mathrm{~V}, 88$$ watt. The current in the secon...

The amplitude of the charge oscillating in a circuit decreases exponentially as $$Q=Q_0 e^{-R t/2 L}$$, where $$Q_0$$ is the charge at $$t=0 \mathrm{~...

In an ideal transformer, the turns ratio is $$\frac{N_P}{N_S}=\frac{1}{2}$$. The ratio $$V_S: V_P$$ is equal to (the symbols carry their usual meaning...

A $$10 \mu \mathrm{F}$$ capacitor is connected to a $$210 \mathrm{~V}, 50 \mathrm{~Hz}$$ source as shown in figure. The peak current in the circuit is...

An ac source is connected in the given circuit. The value of $\phi$ will be : ...

If Z$$_1$$ and Z$$_2$$ are the impedances of the given circuits (a) and (b) as shown in figures, then choose the correct option ...

The maximum power is dissipated for an ac in a/an:

For very high frequencies, the effective impedance of the circuit (shown in the figure) will be:- ...

In a series LCR circuit, the inductance $$L$$ is $$10 ~\mathrm{mH}$$, capacitance $$C$$ is $$1 ~\mu \mathrm{F}$$ and resistance $$R$$ is $$100 ~\Omega...

A $$12 \mathrm{~V}, 60 \mathrm{~W}$$ lamp is connected to the secondary of a step down transformer, whose primary is connected to ac mains of $$220 \m...

An ac source is connected to a capacitor C. Due to decrease in its operating frequency

The magnetic energy stored in an inductor of inductance $$4 ~\mu \mathrm{H}$$ carrying a current of $$2 \mathrm{~A}$$ is :

The net impedance of circuit (as shown in figure) will be : ...

Given below are two statements Statement I : In an a.c circuit, the current through a capacitor leads the voltage across it. Statement II : In a.c cir...

An inductor of inductance 2 mH is connected to a 220 V, 50 Hz ac source. Let the inductive reactance in the circuit is X1. If a 220 V dc source replac...

A standard filament lamp consumes 100 W when connected to 200 V ac mains supply. The peak current through the bulb will be :

The peak voltage of the ac source is equal to

A series LCR circuit with inductance 10 H, capacitance 10 $$\mu$$F, resistance 50 $$\Omega$$ is connected to an ac source of voltage, V = 200sin(100t)...

An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance 'R' are connected in series to an ac source of potential differ...

A capacitor of capacitance 'C', is connected across an ac source of voltage V, given by V = V0sin$$\omega$$tThe displacement current between the plate...

A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44W lamp. Ignoring power losses in the transformer, what ...

A series LCR circuit containing 5.0 H inductor, 80$$\mu$$F capacitor and 40$$\Omega$$ resistor is connected to 230V variable frequency ac source. The ...

A 40 $$\mu $$F capacitor is connected to a 200 V. 50 Hz ac supply. The rms value of the current on the circuit is, nearly :

A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is $${...

The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance

An inductor 20 mH, a capacitor 100 $$\mu $$F and a resistor 50 $$\Omega $$ are connected in series across a source of emf, V = 10 sin 314 t. The power...

Figure shows a circuit that contains three identical resistors with resistance R = 9.0 $$\Omega $$ each, two identical inductors with inductance $$L$$...

Which of the following combinations should be selected for better tuning of an L-C-R circuit used for combination ?

The potential differences across the resistance, capacitance and inductance are 80 V, 40 V and 100 V respectively in an L-C-R circuit. The power facto...

A 100 $$\Omega $$ resistance and a capacitor of 100 $$\Omega $$ reactance are connected in series across a 220 V source. When the capacitor is 50% cha...

A small signal voltage V(t) = V0 sin$$\omega $$t is applied across an ideal capacitor C

An inductor 20 mH, a capacitor 50 $$\mu F$$ and a resistor 40 $$\Omega $$ are connected in series across a source of emf V = 10 sin 340t. The power lo...

A series R-C circuit is connected to an alternating voltage source. Consider two situations : (a)  When capacitor is air filled. (b) ...

A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance...

A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6 A, the voltage across the ...

The primary of a transformer when connected to a dc battery of 10 Volt draws a current of 1 mA. The number of turns of the primary and secondary windi...

A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when

The instantaneous values of alternating current and voltage in a circuit are given as $$i = {1 \over {\sqrt 2 }}$$ sin (100 $$\pi $$t) ampere $$e = {...

The current $$(I)$$ in the inductance is varying with time according to the plot shown in figure. Which one of the following is the correct variation...

In an electrical circuit R, L, C and a.c. voltage source are all connected in series. When L is removed from the circuit, the phase difference between...

The r.m.s. value of potential difference V shown in the figure is ...

A coil has resistance 30 ohm and inductive reactance 20 ohm at 50 Hz frequency. If an ac source, of 200 volt, 100 Hz, is connected across the coil, th...

In the ac circuit an alternating voltage e = $$200\sqrt 2 $$sin100t volts is connected to a capacitor of capacity 1 $$\mu $$F. The r.m.s. value of th...

An ac voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both equal to 3 $$\Omega $$, the phase d...

A condenser of capacity C is charged to a potential difference of V1. The plates of th condenser are then connected to an ideal inductor of inductance...

In the given circuit the reading of voltmeter V1 and V2 are 300 volts each. The reading of the voltmeter V3 and ammeter A are respectively ...

A 220 volt input is supplied to a transformer. The output circuit draws a current of 2.0 ampere at 440 volts. If the efficiency of the transformer is ...

Power dissipated in an LCR series circuit connected to an A.C. source of emf $$\varepsilon $$ is

In an a.c. circuit the e.m.f. ($$\varepsilon $$) and the current (i)  at any instant are given respectively by $$\varepsilon $$ = E0sin$$\...

A transformer is used to light a 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 amp, the efficiency of the transformer is approxi...

What is the value of inductance L for which the current is maximum in a series LCR circuit with C = 10 $$\mu $$F and $$\omega $$ = 1000 s$$-$$1 ? ...

The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux $$\phi $$ linked with the primary coil is g...

A coil of inductive reactance 31 $$\Omega $$ has a resistance of 8 $$\Omega $$. It is placed in series with a condenser of capacitative reactance 25 $...

The core of a transformer is laminated because

A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of fre...

In a circuit L, C and R are connected in series with an alternating voltage source of frquency $$f.$$ The current leads the voltage by 45o. The value ...

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. Th...

For a series LCR circuit the power loss at resonance is

A capacitor of capacity C has reactance X. If capacitance and frequency become double then reactance will be

The value of quality factor is