The potential difference \(V_\mathrm{A}-V_\mathrm{B}\) between the points \(\mathrm{A}\) and \(\mathrm{B}\) in the given figure is:
1. | \(-3~\text{V}\) | 2. | \(+3~\text{V}\) |
3. | \(+6~\text{V}\) | 4. | \(+9~\text{V}\) |
1. | \(\dfrac{a^3R}{3b}\) | 2. | \(\dfrac{a^3R}{2b}\) |
3. | \(\dfrac{a^3R}{b}\) | 4. | \(\dfrac{a^3R}{6b}\) |
Two metal wires of identical dimensions are connected in series. If \(\sigma_1~\text{and}~\sigma_2\)
1. | \(\frac{2\sigma_1 \sigma_2}{\sigma_1+\sigma_2}\) | 2. | \(\frac{\sigma_1 +\sigma_2}{2\sigma_1\sigma_2}\) |
3. | \(\frac{\sigma_1 +\sigma_2}{\sigma_1\sigma_2}\) | 4. | \(\frac{\sigma_1 \sigma_2}{\sigma_1+\sigma_2}\) |
\(\mathrm{A, B}~\text{and}~\mathrm{C}\) are voltmeters of resistance \(R\), \(1.5R\) and \(3R\) respectively as shown in the figure above. When some potential difference is applied between \(\mathrm{X}\) and \(\mathrm{Y}\), the voltmeter readings are \({V}_\mathrm{A}\), \({V}_\mathrm{B}\) and \({V}_\mathrm{C}\) respectively. Then:
1. | \({V}_\mathrm{A} ={V}_\mathrm{B}={V}_\mathrm{C}\) | 2. | \({V}_\mathrm{A} \neq{V}_\text{B}={V}_\mathrm{C}\) |
3. | \({V}_\mathrm{A} ={V}_\mathrm{B}\neq{V}_\mathrm{C}\) | 4. | \({V}_\mathrm{A} \ne{V}_\mathrm{B}\ne{V}_\mathrm{C}\) |
1. | current density | 2. | current |
3. | drift velocity | 4. | electric field |
Two cities are \(150~\text{km}\) apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is \(8\) volts and the average resistance per km is \(0.5~\text{ohm}\). The power loss in the wire is:
1. \(19.2~\text{W}\)
2. \(19.2~\text{kW}\)
3. \(19.2~\text{J}\)
4. \(12.2~\text{kW}\)
The figure given below shows a circuit when resistances in the two arms of the meter bridge are \(5~\Omega\) and \(R\), respectively. When the resistance \(R\) is shunted with equal resistance, the new balance point is at \(1.6l_1\). The resistance \(R\) is:
1. \(10~\Omega\)
2. \(15~\Omega\)
3. \(20~\Omega\)
4. \(25~\Omega\)
A wire of resistance \(4~\Omega\) is stretched to twice its original length. The resistance of a stretched wire would be:
1. | \(4~\Omega\) | 2. | \(8~\Omega\) |
3. | \(16~\Omega\) | 4. | \(2~\Omega\) |