If there are two bulbs of (\(40~\text{W},200~\text{V}\)), and (\(100~\text{W},200~\text{V}\)), then the correct relation for their resistance is:
1. \(R_{40}<R_{100}\)
2. \(R_{40}>R_{100}\)
3. \(R_{40}=R_{100}\)
4. no relation can be predicted
When three identical bulbs are connected in series, the consumed power is \(10\) W. If they are now connected in parallel then the consumed power will be:
1. \(30\) W
2. \(90\) W
3. \(\frac{10}{3}\) W
4. \(270\) W
The current in \(8~\Omega\) resistance is (in the figure below):
1. \(0.69\) A
2. \(0.92\) A
3. \(1.30\) A
4. \(1.6\) A
The terminal potential difference of a cell is greater than its emf when:
1. | A battery of less emf is connected in its series. |
2. | A battery of higher emf is connected in its series. |
3. | A battery of higher emf is connected in its parallel. |
4. | A battery of less emf is connected in its parallel. |
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. \(\frac{3V}{R}\)
The specific resistance of a conductor increases with:
1. | increase in temperature. |
2. | increase in cross-section area. |
3. | increase in cross-section and decrease in length. |
4. | decrease in cross-section area. |
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. | \(\dfrac{10}{9}~ \Omega\) | 2. | \(\dfrac{9}{10}~ \Omega\) |
3. | \(\dfrac{11}{9}~ \Omega\) | 4. | \(\dfrac{5}{9}~ \Omega\) |
In a Wheatstone bridge, all four arms have equal resistance \(R.\) If the resistance of the galvanometer arm is also \(R,\) the equivalent resistance of the combination is:
1. | \(R/4\) | 2. | \(R/2\) |
3. | \(R\) | 4. | \(2R\) |
A car battery of emf \(12~\text{V}\) and internal resistance \(5\times 10^{-2}~\Omega\) receives a current of \(60~\text{A}\) from an external source. The terminal voltage of the battery is:
1. | \(12~\text{V}\) | 2. | \(9~\text{V}\) |
3. | \(15~\text{V}\) | 4. | \(20~\text{V}\) |