Industrial Electronics

81. When SCR starts conducting, then _________ losses all control.

1. gate
2. anode
3. cathode
4. anode supply

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82. When the emitter terminal of a UJT is open, the resistance between the base-terminals is generally

1. low
2. extremely low
3. high
4. extremely high

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83. When the firing angle of SCR is increased, its output

1. decreases
2. increases
3. remains unchanged
4. doubles

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84. When the SCR is OFF, the current in the circuit is

1. exactly zero
2. large leakage current
3. small leakage current
4. thermal current

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85. When the supply voltage exceeds the breakover voltage of an SCR, it

1. starts conducting
2. stops conducting
3. conducts leakage current
4. conducts terminal current

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86. When the temperature increases, the inter-base resistance of a UJT

1. Remains unchanged
2. Increases
3. Decreases
4. is zero

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87. When the temperature increases, the intrinsic stand off ratio

1. increases
2. decreases
3. essentially constant
4. becomes zero

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88. When UJTs is turned on, the resistance between emitter terminal and lower base terminal

1. remains unchanged
2. increases
3. decreases
4. becomes zero

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89. Which device does not have a gate terminal?

1. Triac
2. SCR
3. FET
4. Diac

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90. Which device exhibits negative resistance region?

1. Diac
2. Triac
3. Transistor
4. UJT

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