The variation of EMF with time for four types of generators is shown in the figures. Which amongst them can be called AC voltage?

(a)	(b)
(c)	(d)

1.	(a) and (d)
2.	(a), (b), (c), and (d)
3.	(a) and (b)
4.	only (a)

In a heating arrangement, an alternating current having a peak value of \(28~\mathrm{A}\) is used. To produce the same heat energy, if direct current is used to produce the same amount of heat, then its magnitude will be:

The instantaneous values of alternating current and voltages in a circuit are given as,
\(i=\frac{1}{\sqrt{2}}\sin\left ( 100\pi t \right )~\text{Ampere}\)
\(e=\frac{1}{\sqrt{2}}\sin\left ( 100\pi t+\pi /3 \right )~\text{Volt}\)
What is the average power consumed by the circuit in watts?

For a series \(\mathrm{LCR}\) circuit, the power loss at resonance is:
1. \(\frac{V^2}{\left[\omega L-\frac{1}{\omega C}\right]}\)

2. \( \mathrm{I}^2 \mathrm{~L} \omega \)

3. \(I^2 R\)

4. \( \frac{\mathrm{V}^2}{\mathrm{C} \omega} \)

A light bulb is rated at \(100~\text{W}\) for a \(220~\text{V}\) AC supply. The RMS current through the bulb is:
1. \(0.243\) A
2. \(0.454\) A
3. \(0.222\) A
4. \(0.312\) A

A \(15.0~\mathrm{\mu F}\) capacitor is connected to a \(220~\mathrm{V}\), \(50~\mathrm{Hz}\) source. If the frequency is doubled, what happens to the capacitive reactance and the current?

A resistor of \(200~\mathrm{\Omega}\) and a capacitor of \(15.0~\mu\text{F}\) are connected in series to a \(220~\text{V}\), \(50\) Hz AC source. The voltage (RMS) across the resistor and the capacitor are respectively:
1. \( 160.3 ~\text{V}, 160.3 ~\text{V} \)
2. \( 151 ~\text{V}, 151 ~\text{V} \)
3. \( 160.3 ~\text{V}, 151 ~\text{V} \)
4. \( 151 ~\text{V}, 160.3 ~\text{V}\)

An AC source is rated \(220~\mathrm{V}\), \(50~\mathrm{Hz}\). The average voltage is calculated in a time interval of \(0.01~\mathrm{s}\). It,

An AC source rated \(100~\text{V}\) (rms) supplies a current of \(10~\text{A}\) (rms) to a circuit. The average power delivered by the source:

A transformer is used to light a \(100~\text{W}\) and \(110~\text{V}\) lamp from a \(220~\text{V}\) main. If the main current is \(0.5~\text{A}\), the efficiency of the transformer is approximately:
1. \(30\%\)
2. \(50\%\)
3. \(90\%\)
4. \(10\%\)