In the operation of n-p-n transistor compared to that of a triode, the p base acts as

• emitter

• cathode

• grid

• plate

62.

In the diagram, the input AC is across the terminals A and C. The output across B and D is

          

• same as the input

• half wave rectified

• zero

• full wave rectified

A common emitter amplifier gives an output of 3 V for an input of 0.01 V. If β of the transistor is 100 and the input resistance is 1 kΩ, then the collector resistance is

• 1 kΩ

• 3 kΩ

• 30 kΩ

• 30 kΩ

The combination of the following gates produces

• AND gate

• NAND gate

• NOR gate

• OR gate

When the forward bias voltage of a diode is changed from 0.6 V to 0.7 V, the current changes from 5 mA to 15 mA. Then its forward bias resistance is

• 0.01 Ω

• 0.1 Ω

• 10 Ω

• 100 Ω

In common emitter amplifier, the current gain is 62. The collector resistance and input resistance are 5 kΩ and 500 Ω respectively. If the input voltage is 0.1 V, the output voltage is

• 0.61 V

• 6.2 V

• 62 V

• 620 V

The current gain of a transistor in common base mode is 0.995. The current gain of the same transistor in common emitter mode is

• 197

• 201

• 199

• 202

The real time variation of input signals A and B are as shown below. If the inputs are fed into NAND gate, then select the output signal from the following

The time variations of signals are given as in A, B and C. Point out the true statement from the following

• A, B and C are analogue signals

• A and B are analogue, but C is digital signal

• A and C digital, but B is analogue signal

• A and C are analogue but B is digital signal

The energy gap between conduction band and the valence band is of the order of 0.7 eV. Then it is

• an insulator

• a conductor

• a semiconductor

• an alloy