A transistor is operated in a common emitter configuration at V_c =2 V such that a change in the base current from 100 $\mu A$ to 300 $\mu A$ produces a change in the collector current from 10 mA to 20mA. The current gain is:

1.  75

2.  100 

3.  25

4.  50

A common emitter amplifier has a voltage gain of 50, an input impedance of 100 Ω and an output impedance of 200 Ω. The power gain of the amplifier is:

1. 500

2. 1000

3. 1250

4. 50

To get an output Y = 1 from the circuit shown below, the input must be:

1. A=0 B=1 C=0

2. A=0 B=0 C=1

3. A=1 B=0 C=1

4. A=1 B=0 C=0

The circuit is equivalent to: 
 

1. AND gate

2. NAND gate

3. NOR gate

4. OR gate

In the following circuit, the output Y for all possible inputs A and B is expressed by the truth table: 
    
 

In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an: 

1. p-type semiconductor

2. insulator

3. metal

4. n-type semiconductor

A transistor is operated in a common emitter configuration at constant collector voltage V_c = 1.5 V such that a change in the base current from 100 μA to 150 μA produces a change in the collector current from 5 mA to 10 mA. The current gain (β) is:

1. 67

2. 75

3. 100

4. 50

Which of the following is an example of forward biasing?
 

1.		2.
3.		4.

The following figure shows a logic gate circuit with two inputs A and B and the output C. The voltage waveforms of A, B, and C are as shown below:
   
The logic circuit gate is:

1. AND gate

2. NAND gate

3. NOR gate

4. OR gate