The equivalent resistance between \(A\) and \(B\) for the mesh shown in the figure is:
1. | \(7.2\) \(\Omega\) | 2. | \(16\) \(\Omega\) |
3. | \(30\) \(\Omega\) | 4. | \(4.8\) \(\Omega\) |
Two solid conductors are made up of the same material and have the same length and the same resistance. One of them has a circular cross-section of area and the other one has a square cross-section of area . The ratio is:
1. | \(1.5\) | 2. | \(1\) |
3. | \(0.8\) | 4. | \(2\) |
A \(5-\)ampere fuse wire can withstand a maximum power of \(1\) watt in a circuit. The resistance of the fuse wire is:
1. | \(5\) \(\Omega\) | 2. | \(0.04~\Omega\) |
3. | \(0.2~\Omega\) | 4. | \(0.4~\Omega\) |
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%
Twelve wires of equal resistance R are connected to form a cube. The effective resistance between two diagonal ends A and E will be:
1.
2.
3.
4.
A charged particle having drift velocity of \(7.5\times10^{-4}~\text{ms}^{-1}\) in an electric field of \(3\times10^{-10}~\text{Vm}^{-1}\), has mobility of:
1. \(2.5\times 10^{6}~\text{m}^2\text{V}^{-1}\text{s}^{-1}\)
2. \(2.5\times 10^{-6}~\text{m}^2\text{V}^{-1}\text{s}^{-1}\)
3. \(2.25\times 10^{-15}~\text{m}^2\text{V}^{-1}\text{s}^{-1}\)
4. \(2.25\times 10^{15}~\text{m}^2\text{V}^{-1}\text{s}^{-1}\)
For the given circuit, the value of the resistance in which the maximum heat is produced is:
1. 2
2. 6
3. 4
4. 12
A potential divider is used to give outputs of 2 V and 3 V from a 5 V source, as shown in the figure.
Which combination of resistances, from the ones given below, give the correct voltages?
1. | \(\mathrm{R}_1=1 \mathrm{k} \Omega, \mathrm{R}_2=1 \mathrm{k} \Omega, \mathrm{R}_3=2 \mathrm{k} \Omega\) |
2. | \(\mathrm{R}_1=2 \mathrm{k} \Omega, \mathrm{R}_2=1 \mathrm{k} \Omega, \mathrm{R}_3=2 \mathrm{k} \Omega\) |
3. | \(\mathrm{R}_1=1 \mathrm{k} \Omega, \mathrm{R}_2=2 \mathrm{k} \Omega, \mathrm{R}_3=2 \mathrm{k} \Omega\) |
4. | \(\mathrm{R}_1=3 \mathrm{k} \Omega, \mathrm{R}_2=2 \mathrm{k} \Omega, \mathrm{R}_3=2 \mathrm{k} \Omega\) |
Two batteries, one of emf 18V and internal resistance 2 and the other of emf 12 V and internal resistance 1 are connected as shown. Reading of the voltmeter is:
(if voltmeter is ideal)
1. 14 V
2. 15 V
3. 18 V
4. 30 V
Current through the \(2~\Omega\) resistance in the electrical network shown is:
1. | zero | 2. | \(1\) A |
3. | \(3\) A | 4. | \(5\) A |