| 1. | Out of the following which is an insulating material ? | |
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Copper
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Gold
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Silver
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Paper
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Report Question| 2. | With rise in temperature the resistance of semi-conductors ? | |
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decreases
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increases
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first increases and then decreases
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remains constant
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| 3. | Which of the following materials has a negative temperature co-efficient of resistance ? | |
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Copper
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Carbon
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Aluminum
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Brass
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| 4. | The filament of an electric bulb is made of ? | |
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carbon
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aluminium
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tungsten
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nickel
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| 5. | With rise in temperature the resistance of pure metals ? | |
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increases
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decreases
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first increases and then decreases
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remains constant
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| 6. | The ratio of mass of proton to that of electron is nearly ? | |
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1840
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1840
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30
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4
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| 7. | If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes ? | |
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0.4 ohm
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0.6 ohm
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0.8 ohm
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1.0 ohm
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| 8. | Ohm's law is not applicable to ? | |
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vacuum tubes
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carbon resistors
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high voltage circuits
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circuits with low current densities
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| 9. | Three resistances of 10 ohms, 15 ohms and 30 ohms are connected in parallel. The total resistance of the combination is ? | |
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5 ohms
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10 ohms
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15 ohms
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65 ohms
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| 10. | A thermistor has ? | |
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positive temperature coefficient
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negative temperature coefficient
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zero temperature coefficient
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variable temperature coefficient
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