1. A p-n junction diode is said to be forward biased when:

a) No potential difference is applied across p and n regions

b) A potential difference is applied across p and n regions making p region negative and n region negative.

c) A potential difference is applied across p and n regions making p region negative and n region positive.

d) A magnetic field is applied in the region of junction.

2. When a p-n junction is forward biased then width of deletion region:

a) Increases

b) Decreases

c) Remains unchanged

d) Is variable

3. Circuit is used to convert pulsating D.C into pure D.C is called:

a) Rectifier

b) Inverter

c) Filter

d) Converter

4. In transistor, which region is the thinnest?

a) Emitter

b) Base

c) Collector

d) All have same thickness

5. In normally operating common emitter transistor ,Vcc is:

a) Greater than VBB always

b) Equal to VBB

c) Less than vBB

d) Greater than or equal to VBB

6. β=Ic / IB

a) Voltage gain

b) Resistance gain

c) Current gain

d) Power gain

7. Transistor can be used as:

a) Filter

b) Amplifier

c) Switch

d) Both b and c

8. A diode characteristics curve is a plot between

a) Voltage and time

b) Current and time

c) Voltage and current

d) All of these

9. When a diode is reverse biased, then its resistance of the order of:

a) Ohms

b) Kilo ohms

c) Mega ohms

d) Micro ohms

10. Which device is used as a rectifier?

a) LED

b) Photodiode

c) Transistors

d) Photovoltaic cell

11. Seven segments display is made of

a) LED

b) Photodiode

c) Transistors

d) Photovoltaic cell

12. Which diode is used for detection of light?

a) LED

b) Photodiode

c) Transistors

d) Photovoltaic cell

13. If a diode is reversed biased, then width of depletion region -________ and potential barrier is __________

a) Increase, decrease

b) Decrease, increase

c) Decreases, decreases

d) Increases, increases

14. When a transistor acts as OFF switch, VBE is _______ is VCC

a) Equal to

b) Less than

c) Greater than

d) Zero

15. The slope of current-voltage characteristics curve of semiconductor diode gives:

a) Resistance

b) Conductance

c) Reciprocal of resistance

d) Both b and c

16. When a photovoltaic cell is connected across a resistor and exposed to light, its P-terminal behaves as _____ and N-terminal behaves as _____

a) Positive, Negative

b) Negative, Positive

c) Positive, Positive

d) Negative, Negative

17. The collector of current of a transistor is 10mA and base current is 40 µA. What current gain transistor is ?

a) 500

b) 250

c) 100

d) 750

18. Which region of a transistor contain maximum impurity ?

a) Collector , Emitter

b) Base, Collector

c) Emitter , Collector

d) Emitter, Base

19. Which expression is not written correctly>?

a) β= I /I -1

b) I = (β+1/ β)I

c) I =(β/ β+1)I

d) Both a and c

20. The number of input terminal of an ordinary Op-amp are

a) Two

b) Three

c) Four

d) Eight

21. The magnitude of “Open loop gain” of an amplifier is of the order of:

a) 105Ω

b) 105 A

c) 105 V

d) 105

22. An Op-Amp can be used as:

a) Inverting and non-inverting amplifier

b) Comparator

c) Night switch

d) All of the above

23. The closed loop Gain “G” of the non-inverting amplifier can be expressed by:

a) G = -R2/R1

b) G = 1+R2/R1

c) G = R2/R1

d) G = 1-R1/R2

24. An Op-Amp will act as a non- inverting amplifier when input signal is not connected to

a) Non-inverting input

b) Inverting input

c) Non-inverting output

d) Inverting output

25. An Op-Amp will not act as a non- inverting amplifier when input signal is connected to

a) Non-inverting input

b) Inverting input

c) Non-inverting output

d) Inverting output

26. The gain of an inverting amplifier having external resistance R1=50 kΩ and R2=200kΩ respectively will be:

a) 4

b) 20

c) -20

d) -4

27. An OR gates includes:

a) One input and one output

b) Always two input and one output

c) Two or more input and one output

d) One input and two output

28. XOR gate output can only show a value 1 when its input are:

a) Same

b) Different

c) Both a and b

d) None of these

29. The output of an XNOR gate will be zero only when

a) One of its output is zero

b) Both inputs are zero

c) Both inputs are at one

d) None of these

30. The output of AND gate will be zero when:

a) Both inputs are at zero

b) At least one input is zero

c) At least one of its input is one

d) All of the above

31. The output of AND gate will be one when:

a) Both the inputs are at one

b) Both the inputs are at zero

c) Any one of its input is one

d) All of the above

32. A NOT gate can be used as an inverter to change

a) 1 to 0 only

b) 0 to 1 only

c) 1 to 0 and 0 to 1

d) None of these

33. Which of the following gates corresponds to the truth table given below?

A                 B         Y 1                  1          0 1                  0          1 0                  1          1 0                  0          1

a) XOR

b) OR

c) NAND

d) NOR

34. For which gate the output will be 1 only if both inputs are different :

a) XNOR

b) XOR

c) OR

d) NAND