If the power dissipated in \(5~\Omega\) is \(20\) W then the power dissipated in \(4~\Omega\) is:
   
1. \(4\) W
2. \(6\) W
3. \(10\) W 
4. \(20\) W

The terminal potential difference of a cell is greater than its emf when:

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:

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:

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. ${10}^{-8}$ $V/m$