GATE EC||ELECTRONIC DEVICES AND TECHNOLOGY||SPECIAL DIODE||PYQS(2000-2025)

Last Updated :
Discuss
Comments

Question 1

A particular green LED emits light of wavelength 5490 Å. The energy band gap of the semiconductor material used there is (Plank’s constant [Tex]h = 6.626 \times 10^{-34} \text{ J-s}[/Tex])
( GATE 2003 || EC || MCQ ||1 MARK)

  •  2.26 eV

  •  1.98 eV

  • 1.17 eV

  • 0.74 eV

Question 2

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

(GATE 2003 || EC || MCQ ||1 MARK)

  • X : reverse, Y : reverse

  •  X : reverse, Y : forward

  •  X : forward, Y : reverse

  • X : forward, Y : forward

Question 3

Match items in Group-1 with items in Group-2, most suitably.

Group-1

P. LED

Q. Avalanche

R. Tunnel diode

S. LASER

Group-2

1. Heavy doping

2.Coherent radiation 

3.Spontaneous emission

4. Current gain

(GATE 2003 || EC || MCQ ||1 MARK)

  • P - 1; Q – 2; R – 4; S–3

  •  P – 2; Q –3; R – 1; S–4

  • P – 3; Q – 4; R –1; S–2

  •  P – 2; Q – 1; R – 4; S–3

Question 4

Find the correct match between Group 1 and Group 2

Group 1

E. Varactor-diode

F. PIN diode

G. Zener diode

H. Schottky diode

Group 2

1. Voltage reference

2. High-frequency switch

3. Tuned circuits

4. Current controlled attenuator


( GATE 2006 || EC || MCQ ||1 MARK)

  •  E–4, F–2, G–1, H–3

  •  E–2, F–4, G–1, H–3

  • E–3, F–4, G–1, H–2

  •  E–1, F–3, G–2, H–4

Question 5

Group I lists four types of p-n junction diodes. Match each device in Group I with one of the options in Group II to indicate the bias condition of that device in its normal mode of operation.

Group I Group II

P. Zener Diode 1. Forward bias

Q. Solar cell 2. Reverse bias

R. LASER diode

S. Avalanche Photodiode


(GATE 2008 || EC || MCQ ||1 MARK)

  •  P–1, Q–2, R–1, S–2


  •  P–2, Q–1, R–1, S–2


  • P–2, Q–2, R–2, S–1


  • P–2, Q–1, R–2, S–2


Question 6

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

(R) LASER diode

(3) Early effect

(S) JFET

(4) Flat band voltage

(GATE 2008 || EC || MCQ ||1 MARK)

  •  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


Question 7

Consider the following assertions.

[Tex]S_1[/Tex]: For the Zener effect to occur, a very abrupt junction is required

[Tex]S_2[/Tex]: For quantum tunneling to occur, a very narrow energy barrier is required. Which of the following is correct?


(GATE 2008 || EC || NAT ||1 MARK)

  •  Only S2 is true.

  • S1 and S2 are both true but S2 is not a reason for S1.

  •  S1 and S2 are both true and S2 is a reason for S1.

  •  Both S1 and S2 are false.

Question 8

A Zener diode, when used in voltage stabilization circuits, is biased in  


(GATE 2011 || EC || MCQ ||1 MARK)

  • reverse bias region below the breakdown voltage

  • reverse breakdown region.

  • forward bias region

  • forward bias constant current mode

Question 9

 A pn junction solar cell of area 1.0 cm2, illuminated uniformly with 100mW cm-2, has the following parameters:

Efficiency = 15%, open circuit voltage = 0.7 V, fill factor
= 0.8, and thickness = 200 um. The charge of an electron 1.6 × 10-19 C. The average optical generation rate (in cm-3s-1) is


(GATE 2020 || EC || MCQ ||1 MARK)

  •  1.04 × 1019.

  • 0.84 × 1019.

  • 5.57 × 1019.

  • 83.60 × 1019.

Question 10

A solar cell of area 1.0 cm2, operating at 1.0 sun intensity, has a short circuit current of 20 mA, and an open circuit voltage of 0.65 V. Assuming room temperature operation and thermal equivalent voltage of 26 mV, the open circuit voltage (in volts, correct to two decimal places) at 0.2 sun intensity is ___.


(GATE 2018 || EC || NAT ||1 MARK)

  • 0.59 to 0.63

Tags:
GATE

There are 15 questions to complete.

Take a part in the ongoing discussion