What is the equivalent resistance between A and B in the figure below if R = 3 ?
1. 9
2. 12
3. 15
4. None of these
The potentiometer wire AB is 600 cm long. At what distance from A should the jockey J touch the wire to get zero deflection in the galvanometer?
1. 320 cm
2. 120 cm
3. 20 cm
4. 450 cm
A torch bulb rated 4.5 W, 1.5 V is connected as shown in the figure below. The emf of the cell needed to make the bulb glow at full intensity is:
1. 4.5 V
2. 1.5 V
3. 2.67 V
4. 13.5 V
The metre bridge shown is in a balanced position with \(\frac{P}{Q} = \frac{l_1}{l_2}\). If we now interchange the position of the galvanometer and the cell, will the bridge work? If yes, what will be the balanced condition?
1. Yes, \(\frac{P}{Q}=\frac{l_1-l_2}{l_1+l_2}\)
2. No, no null point
3. Yes, \(\frac{P}{Q}= \frac{l_2}{l_1}\)
4. Yes, \(\frac{P}{Q}= \frac{l_1}{l_2}\)
The figure below shows currents in a part of the electric circuit. The current \(i\) is:
1. \( 1.7 \mathrm{~A} \)
2. \( 3.7 \mathrm{~A} \)
3. \( 1.3 \mathrm{~A} \)
4. \( 1 \mathrm{~A}\)
In the following circuit, the battery has an e.m.f of 12 volts and zero internal resistance while the battery E has an e.m.f of 2 volts. If the galvanometer G reads zero, then the value of the resistance X in ohms is:
1. 10
2. 100
3. 500
4. 200
A voltmeter of resistance \(660~\Omega\) reads the voltage of a very old cell to be \(1.32\) V while a potentiometer reads its voltage to be \(1.44\) V. The internal resistance of the cell is:
1. \(30~\Omega\)
2. \(60~\Omega\)
3. \(6~\Omega\)
4. \(0.6~\Omega\)
An ammeter A of finite resistance and a resistor R are joined in series to an ideal cell C. A potentiometer P is joined in parallel to R. The ammeter reading is and the potentiometer reading is V0 . P is now replaced by a voltmeter of finite resistance. The ammeter reading now is I and the voltmeter reading is V.
It can be concluded that:
1.
2.
3.
4.
A battery of internal resistance r, when connected across \(2~\Omega\) resistor supplies a current of 4 A. When the battery is connected across a \(5~\Omega\) resistor, it supplies a current of 2 A. The value of r is:
1. | \(2~\Omega\) | 2 | \(1~\Omega\) |
3. | \(0.5~\Omega\) | 4. | Zero |
In the circuit shown in the figure below, the current supplied by the battery is:
1. 2 A
2. 1 A
3. 0.5 A
4. 0.4 A