GATE Electronics & Communication Study Materials

Graduate Apptitude Of Test in Engineering (GATE)

Electronics & Communication Study Materials

1. Zener diode, when used in voltage stabilization circuit is biased in

• Reverse bias region below the breakdown region.
• Reverse breakdown region.
• Forward biased region.
• Forward biased constant current mode.

2. In a Zener diode

• Only the P-region is heavily doped
• Only the N-region is heavily doped
• Both P and N region are heavily doped
• Both P and N region are lightly doped

3. Which of these has highly doped p and n region?

• PIN diode 
• Tunnel diode
• Schottkey diode 
• Photo diode

4. Which of these diodes has the layer of intrinsic semiconductor

• Zener diode 
• PIN diode
• Photo diode 
• Schottkey diode

5. In which of the following diodes the width of junction barrier is very large

• Tunnel diode 
• Photo diode
• PIN diode 
• Schottkey diode

6. Which of these diodes has degenerate p and n material

• Zener diode 
• PIN diode
• Tunnel diode 
• Photo diode

7. Consider the following assertions.
S1: For Zener effect to occur, a very abrupt junction is required
S2: For quantum tunneling to occur, a very narrow energy barrier is required
Which of the following is correct?

• Only S2 is true
• S1 and S2 are both true but S2 is a not a reason for S1
• S1 and S2 are both true but S2 is a reason for S1
• Both S1 and S2 are false

8. Which of these diodes is also called hot carrier diode.

• PIN diode 
• LED
• Photo diode 
• Schottkey diode

9. In which of these diode the reverse recovery time is nearly zero.

• Diode 
• Tunnel Diode
• Schottkey Diode
• PIN Diode

10. In which of the following diodes, the negative resistance region exists, in v-I characteristics

• PIN diode 
• Schottkey diode
• Tunnel diode 
• Zener diode

11. The of doped regions in PIN diode are

• 1 
• 2 
• 3 
• 4

12. Which of the following diode is a voltage controlled capacitor

• Zener diode 
• p n diode
• Varactor diode 
• LED

13. In LED light is emitted because

• Recombination of charge carriers take place
• Diode gets heated up
• Light falling on gets amplified
• Light gets reflected due to lens action

14. GaAs LED emits radiation in

• Ultraviolet region
• Violet, blue, green, range of visible region
• Visible region
• Infrared region

15. Which of these diodes is used in seven segment display

• PIN diode 
• LED 
• Photo diode 
• Tunnel diode

16. The barrier potential of Schottkey diode is

• 0.25V 
• 0.7V
• 0.3V 
• 1.7V

17. The diode which has zero breakdown voltage is

• Zener diode 
• Schottkey diode
• Breakdown diode 
• Tunnel diode

18. The I- V characteristic solar cell lies in

• I quadrant 
• II quadrant
• III quadrant 
• IV quadrant

19. The light emitted by LASER diode is

• Monochromatic 
• Coherent
• Visible 
• First Two

20. The LASER diode sources require

• Spontaneous emission
• Absorption
• Stimulated emission
• None of the above

21. Group I lists four different semiconductor devices. Match each device in Group I with its characteristic property in Group II.
          Group I                              Group II 
P. BJT                               1. Population inversion
Q. MOS capacitor           2. Pinch-off voltage 
R. LASER diode             3. Early effect 
S. JEET                           4. Flat-band voltage

• P-3, Q-1, R-4, S-2
• P-1, Q-4, R-3, S-2
• P-3, Q-4, R-1, S-2
• P-3, Q-2, R-1, S-4

22. SOLAR cells are based on the principle of

• Population inversion
• Stimulated emission
• Photovoltaic
• Emission

23. Solar cells provide electrical power at

• Low cost
• Height cost
• Low installation cost
• Low operating cost

24. Solar cells operate in

• Forward bias 
• Revers bias
• No bias 
• None of the above

25. LCD displays are preferred duce to

• High decay time
• Reflective
• Transmittive
• Low power consumption

26. The sensitivity of a photo diode depends on

• Light intensity & depletion region width
• Depletion region width and excess carrier lifetime
• Excess carrier life time and forward bias current
• Forward bias current and light intensity

27. P-N junction photodiode has to be

• Reverse biased 
• Forward biased
• Switched on 
• Switched off

29. Choose proper substitutes for X and Y to make the following statement correct Tunnel diode and Avalanche photodiode are operated in X bias and Y bias respectively.

• X: reverse, Y: reverse
• X: reverse, Y: forward
• X: forward, Y: reverse
• X: forward, Y: forward

30. For a PN junction match the type of breakdown with phenomenon
          Group -1                                       Group-2
1. Avalanche breakdown    Collision of carriers with crystal ions
2. Zener breakdown            Early effect 
3. Punch through                  Rupture of covalent bond due to strong electric field.

• 1-B, 2-A, 3-C 
• 1-C, 2-A, 3-B
• 1-A, 2-B, 3-C 
• 1-A, 2-C, 3-B

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