Current Electricity

91. When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will

1. decrease
2. increase
3. remain constant
4. none of the above

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92. Whether circuit may be AC. or D.C. one, following is most effective in reducing the magnitude of the current.

1. Reactor
2. Capacitor
3. Inductor
4. Resistor

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93. Which is the best conductor of electricity?

1. Iron
2. Silver
3. Copper
4. Carbon

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94. Which method can be used for absolute measurement of resistances?

1. Lorentz method
2. Releigh method
3. Ohm's law method
4. Wheatstone bridge method

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95. Which of the following can have negative temperature coefficient?

1. Compounds of silver
2. Liquid metals
3. Metallic alloys
4. Electrolytes

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96. Which of the following material has nearly zero temperature co-efficient of resistance?

1. Manganin
2. Porcelain
3. Carbon
4. Copper

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97. Which of the following materials has a negative temperature co-efficient of resistance?

1. Copper
2. Aluminum
3. Carbon
4. Brass

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98. Which of the following materials has the least resistivity?

1. Zinc
2. Lead
3. Mercury
4. Copper

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99. Which of the following quantities remain the same in all parts of a series circuit?

1. Voltage
2. Current
3. Power
4. Resistance

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100. Which of the following statement is correct?

1. A semi-conductor is a material whose conductivity is same as between that of a conductor and an insulator
2. A semi-conductor is a material which has conductivity having average value of conductivity of metal and insulator
3. A semi-conductor is one which con¬ducts only half of the applied voltage
4. A semi-conductor is a material made of alternate layers of conducting material and insulator

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