In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in the USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in the USA will be:

1. 2R
2. R/4
3. R/2
4. R 

A battery is charged at a potential of \(15\) V for \(8\) hours when the current flowing is \(10\) A. The battery on discharge supplies a current of \(5\) A for \(15\) hours. The mean terminal voltage during discharges is \(14\) V. The "Watt hour" efficiency of the battery is:
1. \(80\%\)
2. \(90\%\)
3. \(87.5\%\)
4. \(82.5\%\)

Five equal resistances each of resistance \(R\) are connected as shown in the figure below. A battery of \(V\) volts is connected between \(A\) and \(B\). The current flowing in \(AFCEB\) will be:

   
1. \(\frac{V}{R}\)
2. \(\frac{V}{2R}\)
3. \(\frac{2V}{R}\)
4. \(\frac{3V}{R}\)

A 6-volt battery is connected to the terminals of a three-metre-long wire of uniform thickness and resistance of 100 ohms. The difference of potential between two points on the wire separated by a distance of 50 cm will be:

1. 3 V

2. 1 V

3. 1.5 V

4. 2 V

The specific resistance of a conductor increases with:

For a cell, the terminal potential difference is \(2.2\) V when the circuit is open and reduces to \(1.8\) V when the cell is connected to the resistance of \(R = 5~\Omega\). The internal resistance of cell (\(r\)) is:
1. \(\frac{10}{9}~ \Omega\)
2. \(\frac{9}{10}~ \Omega\)
3. \(\frac{11}{9}~ \Omega\)
4. \(\frac{5}{9}~ \Omega\)

If the specific resistance of a potentiometer wire is ${10}^{-7}$ $\Omega m$ and the current flow through it is 0.1 A, the cross-sectional area of the wire is  ${10}^{-6}$ $m^2$, then potential gradient will be:

1. ${10}^{-2}$ $V/m$

2. ${10}^{-4}$ $V/m$

3. ${10}^{-6}$ $V/m$

4. ${10}^{-8}$ $V/m$

The resistance of each arm of the wheat stone bridge is \(10~ \Omega.\) A resistance of \(10~ \Omega\) is connected in series with a galvanometer. The equivalent resistance across the battery will be:
1.\(10~ \Omega\)
2.\(15~ \Omega\)
3. \(20~ \Omega\)
4. \(40~ \Omega\)

If copper and silicon are cooled from 300 K to 60 K, then the specific resistance will:
1.  Decrease in copper but increase in silicon
2.  Increase in copper but decrease in silicon
3.  Increase in both
4.  Decrease in both

Two 220-volt, 100-watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220-volt a.c. supply line. The power drawn by the combination in each case respectively will be:

1. 50 watt, 100 watt

2. 100 watt, 50 watt

3. 200 watt, 150 watt

4. 50 watt, 200 watt