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

1. 45 A

2. 5.5 A

3. 55 A

4. 0.55 A

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

1. Zero

$2. \frac{\pi }{4}$
$3. \frac{\pi }{4}$
$4. \pi$

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:

1. Zero

2. $\alpha \beta$

3. $\frac{\beta }{\alpha }$

4. $\frac{\alpha }{\beta }$

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

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

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

1. zero

2. 100 V

3. 200 V

4. 400 v

What is the value of the power factor for a parallel LC circuit at a frequency less than the resonance frequency?

1. Zero

2. 1

3. > 1

4.< 1

When an alternating voltage is given as \(E = (6 sin\omega t - 2 cos \omega t)\) volt, what is its RMS value?
1. \(4 \sqrt 2 \) V
2. \(2 \sqrt 5\) V
3. \(2 \sqrt 3\) V
4. \(4\) V

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

1. Pure inductor (L)

2. Pure capacitor (C)

3. Series L-C circuit

4. All of these

An LC circuit contains an inductor (L=25 mH) and a capacitor (C=25 mF) with an initial charge of Q₀. At what time will the circuit have an equal amount of electrical and magnetic energy?

$1.$ $\frac{\mathrm{\pi }}{\mathrm{160 }}s$

$2.$ $\frac{3\mathrm{\pi }}{\mathrm{160 }}s$

$3.$ $\frac{5\mathrm{\pi }}{\mathrm{160 }}s$

4. All of these

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

1. LC circuit

2. LCR circuit

3. Purely resistive circuit

4. Both (1) & (2)