For transistor action:

(a)	the base, emitter and collector regions should have similar size and doping concentrations.
(b)	the base regions must be very thin and lightly doped.
(c)	the emitter-base junction is forward biased and the base-collector junction is reverse biased.
(d)	both the emitter-base junction as well as the base-collector junction are forward biased.

Which of the following pairs of statements is correct?
1. (d) and (a)
2. (a) and (b)
3. (b) and (c)                                       
4. (c) and (d)

The electrical circuit used to get smooth output from a rectifier circuit is called:

1. oscillator.

2. filter.

3. amplifier.

4. logic gates.

The correct symbol for zener diode is:

1.		2.
3.		4.

The emitter-base junction of a transistor is …… biased while the collector-base junction is ……. biased.
1. reverse, forward                       

2. reverse, reverse

3. forward, forward                       

4. forward, reverse

For a transistor, the current amplification factor is 0.8 when it is connected in the common base configuration. The transistor is now connected in common emitter configuration. The change in the collector current when the base current changes by 6 mA, is:
1. 6 mA                       

2. 4.8 mA

3. 24 mA                     

4. 8 mA

Consider an NPN transistor amplifier in the common-emitter configuration. The current gain of the transistor is 100. If the collector current changes by 1 mA, what will be the change in emitter current?
1. 1.1 mA                     

2. 1.01 mA

3. 0.01 mA                   

4. 10 mA

Which of the following logic gate is a universal gate?
1. OR
2. NOT
3. AND
4. NOR

How much is the forbidden gap (approximately) in the energy bands of germanium at room temperature? 
1. \(1.1~\text{eV}\)
2. \(0.1~\text{eV}\)
3. \(0.67~\text{eV}\)
4. \(6.7~\text{eV}\)