1. | \(2~\Omega\) | 2 | \(1~\Omega\) |
3. | \(0.5~\Omega\) | 4. | zero |
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. \(82.5\%\)
A battery of emf \(E\) and internal resistance \(r\) is connected to a variable resistor \(R\) as shown below. Which one of the following is true?
1. | Potential difference across the terminals of the battery is maximum when \(R=r\). |
2. | Power delivered to the resistor is maximum when \(R=r\). |
3. | Current in the circuit is maximum when \(R=r\). |
4. | Current in the circuit is maximum when \(R>>r\). |