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 voltage drop $$\left(V_L\right)$$ across $$L$$ is

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 secondary circuit, ignoring the power loss in the transformer, is

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 $$t=0 \mathrm{~s}$$. The time at which charge amplitude decreases to $$0.50 Q_0$$ is nearly:

[Given that $$R=1.5 \Omega, L=12 \mathrm{~mH}, \ln (2)=0.693$$]

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 nearly $$(\pi=3.14)$$ :

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 $$100 ~\Omega$$. The frequency at which resonance occurs is :-

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 $$220 \mathrm{~V}$$. Assuming the transformer to be ideal, what is the current in the primary winding ?

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 circuit containing pure capacitance only, the phase difference between the current and voltage is $$\pi$$.

In the light of the above statements, choose the most appropriate answer from the options given below

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 replace the ac source in the circuit, then the inductive reactance in the circuit is X₂. X₁ and X₂ respectively are :

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) volt. If the resonant frequency of the LCR circuit is v₀ and the frequency of the ac source is v, then