Q. No.A storage battery of emf 8.0 V and internal resistance 0.5 Ω is being charged by a 120 V dc supply using a series resistor of 15.5 Ω. What is the terminal voltage of the battery during charging?
1. 11.5 V
2. 12 V
3. 13.3 V
4. 10 V
In a potentiometer arrangement, a cell of emf \(1.25\) V gives a balance point at \(35.0\) cm length of the wire. If the cell is replaced by another cell and the balance point shifts to \(63.0\) cm, then the emf of the second cell is:
1. \(1.27\) V
2. \(2.25\) V
3. \(3.27\) V
4. \(3.25\) V
Choose the correct alternative.
| 1. | Alloys of metals usually have less resistivity than that of their constituent metals. |
| 2. | Alloys usually have much higher temperature coefficients of resistance than pure metals. |
| 3. | The resistivity of the alloy manganin is nearly independent with an increase of temperature. |
| 4. | The resistivity of a typical insulator (e.g., amber) is less than that of a metal by a factor of the order of 10 22 / 10 23 . |
Given n resistors each of resistance R, what is the ratio of the maximum to minimum resistance?
1. \(\frac{1}{n}\)
2. \(n\)
3. \(\frac{1}{n^2}\)
4. \(n^2\)
Given the resistances of 1Ω, 2Ω, 3Ω, how will we combine them to get an equivalent resistance of (11/3):
| 1. | 1Ω, 2Ω in parallel and the combination in series with 3Ω |
| 2. | 3Ω, 2Ω in parallel and the combination in series with 1Ω |
| 3. | 1Ω, 2Ω and 3Ω in parallel |
| 4. | 1Ω, 2Ω in series and the combination in parallel with 3Ω |
The number density of free electrons in a copper conductor is 8.5×1028 m–3. How long does an electron take to drift from one end of a wire 3.0 m long to its other end? The area of the cross-section of the wire is 2.0×10–6 m2 and it is carrying a current of 3.0 A.
1.\(2.7 \times10^{4}\) s
2.\(3.3 \times10^{4}\) s
3.\(2.0 \times10^{3}\) s
4.\(3.9 \times10^{3}\) s
Six lead-acid type of secondary cells each of emf \(2.0\) V and internal resistance \(0.015~\Omega\) are joined in series to provide a supply to a resistance of \(8.5~\Omega\). What is the current drawn from the supply?
1. \(2.10\) A
2. \(1.39\) A
3. \(1.71 \) A
4. \(2.21\) A
A secondary cell after long use has an emf of \(1.9\) V and a large internal resistance of \(380\) \(\Omega.\) What maximum current can be drawn from the cell?
1.\(0.05\) A
2. \(0.005\) A
3. \(5.0\) A
4. \(0.5\) A
The storage battery of a car has an emf of \(12\) V. If the internal resistance of the battery is \(0.4~\Omega\), what is the maximum current that can be drawn from the battery?
1. \(30\) A
2. \(20\) A
3. \(10\) A
4. \(40\) A
A battery of emf 10 V and internal resistance is connected to a resistor. If the current in the circuit is 0.5 A, what is the terminal voltage of the battery when the circuit is closed?
1. 10 V
2. 8.5 V
3. 1.5 V
4. 7.2 V
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