1
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Pick out the correct statement from the following;

A

The number density of free electrons in the valance band decides the strength of the electric current

B

Valance band is always completely filled, while conduction band is always partially filled

C

The maximum energy required to shift an electron from the conduction band to valance band is called energy band gap

D

In a semiconductor no free electrons are found in the conduction band at 0 K

2
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

What is the minimum wavelength of radiation required to detect a p-n junction diode made of a semiconductor having band gap 3.3 eV .

[Planck's constant $h=6.6 \times 10^{34} \mathrm{~J} . \mathrm{s}$ ]

A

$3300^{\circ} \mathrm{A}$

B

$4800^{\circ} \mathrm{A}$

C

$3750^{\circ} \mathrm{A}$

D

$7500^{\circ} \mathrm{A}$

3
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Find the current through the $40 \Omega$ resistor in the given circuit having a diode, three resistors and two cells.

COMEDK 2026 Afternoon Shift Physics - Semiconductor Devices and Logic Gates Question 1 English
A

0.21 A

B

0.5 A

C

1.2 A

D

2.1 A

4
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0

In a PN junction diode, the forward bias is increased gradually from 0 Volt to 1 Volt. Which of the following statements is correct?

A. The depletion width increases, and barrier potential increases

B. The depletion width decreases, but the electric field inside the junction increases

C. The depletion width remains unchanged, but current increases

D. The depletion width decreases and barrier potential decreases

A

B

B

A

C

D

D

C

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