An alternating current having a peak value \(14~\text A\) is used to heat a metal wire. To produce the same heating effect, a constant current \(i\) can be used, where the value of \(i\) is:
1. \(14~\text A\) 
2. about \(20~\text A\) 
3. \(7~\text A\) 
4. about \(10~\text A\) 

A constant current of 2.8 A exists in a resistor. The RMS current is

1.  2.8 A

2.  about 2 A

3.  1.4 A

4.  undefined for a direct current

The reactance of a circuit connected to an AC circuit is zero. It is possible that the circuit contains 

(a) an inductor and a capacitor
(b) an inductor but no capacitor
(c) a capacitor but no inductor
(d) neither an inductor nor a capacitor

Choose the correct option

1.  (a) only

2. (b), (c)

3. (c), (d)

4. (a), (d)

In an AC series circuit, the instantaneous current is zero when the instantaneous voltage is maximum. Connected to the source may be a:

Choose the correct option:

An inductor coil having some resistance is connected to an AC source. Which of the following quantities have zero average value over a cycle?

Choose the correct option from the options given below:

The AC voltage across a resistance can be measured using 

(a) a potentiometer
(b) a hot-wire voltmeter
(c) a moving-coil galvanometer
(d) a moving-magnet galvanometer

Choose the correct option 

1. (a), (b)

2. (b) only

3. (c), (d)

4. (a), (d)

To convert mechanical energy into electrical energy, one can use 

(a) DC dynamo
(b) AC dynamo
(c) motor
(d) transformer

Choose the correct option 

1. (a) only

2. (b), (c) 

3. (a), (b) 

4. (a), (d) 

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:

An alternating current is given by 
\(i=i_1 \cos \omega t+i_2 \sin \omega t\)
The rms current is given by:

1.    \(\frac{i_{1}+i_{2}}{\sqrt{2}}\)

2.  \(\frac{\left|i_{1}-i_{2}\right|}{\sqrt{2}}\)

3.   \(\sqrt{\frac{i_{1}^{2}+i_{2}^{2}}{2}}\)

4.  \(\sqrt{\frac{i_{1}^{2}+i_{2}^{2}}{\sqrt{2}}}\)