1
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

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

A silicon sample is doped simultaneously with donor impurity phosphorus at a concentration of $N_D=3 \times 10^{22} \mathrm{~m}^{-3}$ and acceptor impurity boron at a concentration of $N_D=2.8 \times 10^{22} \mathrm{~m}^{-3}$. The intrinsic carrier concentration of silicon at room temperature is $n_i=1.5 \times 10^{16} \mathrm{~m}^{-3}$. Assuming complete ionization, the hole concentration is :

A
$1.125 \times 10^{10} m^{-3}$
B
$1.125 \times 10^{11} \mathrm{~m}^{-3}$
C
$2.125 \times 10^{10} \mathrm{~m}^{-3}$
D
$2.125 \times 10^{11} m^{-3}$
3
COMEDK 2026 Morning Shift
MCQ (Single Correct Answer)
+1
-0
COMEDK 2026 Morning Shift Physics - Semiconductor Devices and Logic Gates Question 4 English

In the circuit given, the reverse breakdown voltage of the Zener diode is 4.8 V . The current through the Zener and the power dissipation in Zener is:

A

$22.4 \mathrm{~mA} ; 107.52 \mathrm{~mW}$

B

$2.88 \mathrm{~mA} ; 13.82 \mathrm{~mW}$

C

$28.8 \mathrm{~mA} ; 138.24 \mathrm{~mW}$

D

$12.4 \mathrm{~mA} ; 97.52 \mathrm{~mW}$

4
COMEDK 2025 Evening Shift
MCQ (Single Correct Answer)
+1
-0

The zener voltage in the circuit shown is $\mathrm{V}_{\mathrm{Z}}=20 \mathrm{~V}$. The load resistance $\mathrm{R}_{\mathrm{L}}=5 \mathrm{k} \Omega$ and the resistance $\mathrm{R}_{\mathrm{S}}=10 \mathrm{k} \Omega$. If the input voltage is $\mathrm{V} \mathrm{s}=100 \mathrm{~V}$, then the current through the zener diode in milliampere is:

COMEDK 2025 Evening Shift Physics - Semiconductor Devices and Logic Gates Question 7 English

A
8
B
6
C
4
D
5

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