| 1. | When current flows through heater coil it glows but supply wiring does not glow because ? | |
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current through supply line flows at slower speed
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supply wiring is covered with insulation layer
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resistance of heater coil is more than the supply wires
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supply wires are made of superior material
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Report Question| 2. | ...... are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators ? | |
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Varistors
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Thermistor
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Semi-conductors
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Variable resistors
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| 3. | Switching of a lamp in house produces noise in the radio. This is because switching operation produces ? | |
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arcs across separating contacts
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mechanical noise of high intensity
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both mechanical noise and arc between contacts
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none of the above
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| 4. | Which method can be used for absolute measurement of resistances ? | |
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Lorentz method
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Releigh method
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Ohm's law method
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Wheatstone bridge method
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| 5. | Which of the following can have negative temperature coefficient ? | |
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Compounds of silver
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Liquid metals
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Metallic alloys
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Electrolytes
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| 6. | Three identical resistors are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be ? | |
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9 times
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1/9 times
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1/3 times
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3 times
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| 7. | Resistance of 220 V, 100 W lamp will be ? | |
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4.84 ?
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48.4 ?
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484 ?
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4840 ?
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| 8. | With three resistances connected in I parallel, if each dissipates ,20 W the total power supplied by the voltage source equals ? | |
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10W
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20 W
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40 W
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60 W
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| 9. | which resistor will be physically larger in size ? | |
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100 ?, 10W
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10 ?, 50 W
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1 M?, 1/2 W
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1 k?, 1 W
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| 10. | A resistance having rating 10 ohms, 10 W is likely to be a ? | |
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metallic resistor
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carbon resistor
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wire wound resistor
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variable resistor
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