In the transformer shown in the figure, the ratio of the number of turns of primary to the secondary is $\frac{N_1}{N_2}=\frac{1}{50}$. If a battery of emf 10 V is connected across primary, then induced current through the load of 10 k$\Omega$ in the secondary is

$$\begin{gathered} 1. \frac{1}{20}A \\ 2. Zero \\ 3. \frac{1}{10}A \\ 4. \frac{1}{5}A \end{gathered}$$

In an ac circuit, the current, i= 100sin100t A and V=100sin$(100\mathrm{t}+\frac{\mathrm{\pi }}{3})$ volt. Then the average power dissipated in the ac circuit is:

EMF induced in the secondary coil of an ideal transformer does not depend upon

The phase difference between emf and current through the choke coil maybe

An ideal transformer is made to step down the power line voltage of 2200 V for distribution to a city at 220 v. If the full load impedance of the city is 4 $\Omega$ then the primary current is

A: Current through a pure inductor is wattless.

R: Phase difference between emf across a pure inductor and current through it is $90° or \frac{\mathrm{\pi }}{2}$.

What is the phase difference between potential difference across the inductor and potential difference across the capacitor in a series LCR circuit?

1. Zero

$$\begin{gathered} 2. \frac{\pi }{4} \\ 3. \frac{\pi }{4} \\ 4. \pi \end{gathered}$$

For a series, LCR circuit quality factor is $\alpha$ and potential difference across circuit $\beta$. The potential difference across the inductor in resonance state will be:

The ratio of current delivered by the battery just after the switch is closed to a long time after the switch closed is

 $$\begin{gathered} 1. \frac{2}{3} \\ 2. \frac{5}{6} \\ 3. \frac{3}{2} \\ 4. \frac{3}{4} \end{gathered}$$

What is the reading of the A.C voltmeter in the network as shown in the figure?

The value of power factor for a parallel LC circuit at a frequency less than resonance frequency is

The RMS value of an alternating voltage given by $E=(6 \sin \omega t -2 \cos \omega t)$ volt is

$$\begin{gathered} 1. 4\sqrt{2} V \\ 2. 2\sqrt{5} V \\ 3. 2\sqrt{3} V \\ 4. 4 V \end{gathered}$$

Current through an elements in ac circuit is said to be wattless, when the elements is

An LC circuit contains an inductor (L=25 mH ) and capacitor (C=25 mF) with an initial charge $Q_0$. After what time will the circuit have an equal amount of electrical and magnetic energy?

In which of the following circuits, the power factor can be zero?

The quality factor of the resonance circuit is given by (symbols have usual meanings)

$$\begin{gathered} 1.\frac{{\omega }_{0}L}{R} \\ 2. \frac{1}{{\omega }_{0}RC} \\ 3. \frac{{\omega }_{0}C }{R} \\ 4. Both \left(1\right) \& \left(2\right) \end{gathered}$$

In the given circuit, switch S is closed at t=0. After a long time, the iron rod is withdrawn from the inductor L. Then, the bulb

The circuit is in a steady state when the key is at position 1. If the switch is changed from position 1 to position 2, then the steady current in the circuit is
                

$$\begin{gathered} 1. \frac{E_0}{R} \\ 2. \frac{E_0}{3R } \\ 3. \frac{E_0}{2R } \\ 4. \frac{E_0}{4R } \end{gathered}$$

LCR series circuit is connected with an alternating emf source. If the peak current and voltage are $l_{0 }and V_0$ respectively then at resonance the value of wattless current is

$$\begin{gathered} 1. l_0 \\ 2. \frac{l_0}{\sqrt{2}} \\ 3. \sqrt{2}{l}_0 \\ 4. zero \end{gathered}$$

The value of quality factor ( Q-value) of the series resonant circuit with inductance L = 2.0 H, capacitance C= 32 $\mu F$ and resistance R = 10 $\Omega$, is

A: When a current $I = (3+4 \sin \omega t)$ flows in a wire, then the reading of a DC ammeter connected in series is 4 units.

R: A d.c. ammeter measures only the value of the current amplitude.

A: A capacitor can replace the choke coils in a.c circuit.

R: A capacitor can reduce the current in a.c. a circuit like an inductor

A: DC and AC both can be measured by a hot wire instrument.

R: A hot wire instrument works on the principle of the magnetic effect of current.

A: When the frequency of the AC source in a series LCR circuit equals to the resonant frequency, the reactance of the circuit is zero.

R: There is maximum current through the inductor as well as a capacitor at resonance.

A 40 $\mathrm{\mu }$F capacitor is connected to a 200 V, 50 Hz ac supply. The RMS value of the current in the circuit is, nearly:

1. 2.05 A

A 100 Ω resistor is connected to a 220 V, 50 Hz ac supply. The net power consumed over a full cycle is:

The rms value of current in an ac circuit is 10 A. The peak current in the circuit is:

(1) 1.41 A

A 44 mH inductor is connected to 220 V, 50 Hz ac supply. The RMS value of the current in the circuit is:

What is the Q-value of a series LCR circuit with L = 2.0 H, C = 32 µF and R = 10 Ω?

A charged 30 µF capacitor is connected to a 27 mH inductor. What is the angular frequency of free oscillations of the circuit?

$$\begin{gathered} \left(1\right) 1.11\times {10}^3 rad/s \\ \left(2\right) 2.11\times {10}^3 rad/s \\ \left(3\right) 1.11\times {10}^2 rad/s \\ \left(4\right) 1.11\times {10}^4 rad/s \end{gathered}$$