| 1. | A constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if ? | |
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the length of the wire is doubled.
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the radius of the wire is doubled.
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both the length and the radius of the wire are halved.
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both the length and the radius of the wire are doubled.
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Report Question| 2. | The relaxation time in conductors ? | |
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decreases with the increases of temperature
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it does not depends on temperature
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increases with the increases of temperature
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all of sudden changes at 400 K
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| 3. | The example of non-ohmic resistance is ? | |
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carbon resistor
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diode
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copper wire
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filament lamp
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| 4. | To draw a maximum current from a combination of cells, how should the cells be grouped ? | |
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Series
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Mixed grouping
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Parallel
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epends upon the relative values of internal and external resistances
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| 5. | For measuring voltage of any circuit, potentiometer is preferred to voltmeter because ? | |
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range of the voltmeter is not as wide as that of the potentiometer.
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the potentiometer almost draws no current during measurement.
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calibration in the voltmeter is sometimes wrong.
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the potentiometer is cheap and easy to handle.
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| 6. | The current which is assumed to be flowing in a circuit from positive terminal to negative, is called ? | |
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conventional current
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alternating current
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pulsating current
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direct current
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| 7. | When there is an electric current through a conducting wire along its length, then an electric field must exist ? | |
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inside the wire but normal to it.
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outside the wire but parallel to it.
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outside the wire but normal to it.
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inside the wire but parallel to it.
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| 8. | Which of the following is wrong? Resistivity of a conductor is ? | |
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less than resistivity of a semiconductor.
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independent of dimensions of conductor.
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independent of temperature.
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inversely proportional to temperature.
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| 9. | The speed at which the current travels, in conductor, is nearly equal to ? | |
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4 × 10^6 m/s
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3 × 10^8 m/s
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3 × 10^5 m/s
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3 × 10^4 m/s
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| 10. | Potentiometer measures potential more accurately because ? | |
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it uses high resistance potentiometer wire
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it measures potential in open circuit
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it measures potential in closed circuit
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it uses sensitive galvanometer for null deflection
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