BJT MCQ

81. If α = o.995, I_E =10mA and I_CO=0.5 μA, then I_CEO will be

1. 100 μA
2. 25 μA
3. 10.1 μA
4. 10.5 μA

82. What does the discharge transistor do in the 555 timer circuit?

1. Discharge the external capacitor to stop the timing
2. Charge the external capacitor to stop the timing
3. Discharge the external capacitor to start the timing over again
4. Charge the external capacitor to start the timing over again

83. Transistors leakage current mainly depends on

1. Doping of base
2. Size of emitter
3. Rating of transistor
4. Temperature

84. Transistors are

1. Low voltage & low current device
2. High voltage & high current device
3. Low voltage and high current device
4. Only low current device

85. How much is the base-to-emitter voltage of a transistor in the ‘ON’ state?

1. Undefined
2. 0.7 V
3. 0 V
4. 0.7 mV

86. A transistor connected in common base configuration has

1. A high input resistance and low output resistance
2. A high input resistance and high output resistance
3. A low input resistance and high output resistance
4. A low input resistance and low output resistance

87. In a PNP transistor, electrons flow

1. Out of the transistor, at the collector and base leads
2. Out of the transistor, at the emitter and base leads
3. Into the transistor, at the emitter and base leads
4. Into the transistor, at the collector and base leads

88. The current gain of a Darlington pair in common emitter configuration is approximately

1. β²
2. 1+β/1-β
3. β/1+β
4. 2β

89. The h-parameter equivalent circuit of a BJT is valid for

1. Large signal operation at high frequencies
2. Small signal operation at low frequencies
3. Large signal operation at low frequencies
4. Small signal operation at high frequencies

90. Of the three BJT configurations CB, CE and CC

1. CB does not have miller effect hence higher bandwidth
2. CC has smallest bandwidth
3. CB exhibits reduction in bandwidth due to miller effect
4. CE exhibits increase in bandwidth due to miller effect.