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Semiconductor Electronics · Question 16

JEE Main 2026 (Online) 23rd January Morning ShiftMCQMedium📈 Topic in 23% papers+4−1
1

The following diagram shows a Zener diode as a voltage regulator. The Zener diode is rated at Vz = 5 V and the desired current in load is 5 mA. The unregulated voltage source can supply up to 25 V. Considering the Zener diode can withstand four times the load current, the value of resistor Rs (shown in circuit) should be . [figure]

  1. 100
  2. 10
  3. 1000
  4. 4000

Answer

(3) 1000

Solution

Maximum current the Zener diode can withstand: IZ, = 4 5 mA = 20 mA

Rs must keep the current within this limit even in the worst case, i.e. at the highest input (25 V) when the whole current may pass through the Zener (load removed).

Voltage across Rs: Vin - Vz = 25 - 5 = 20 V

Rs = 20 V20 10-3 A = 1000

(With the load connected, the 20 mA divides into 5 mA through RL and 15 mA through the Zener, which is within its rating.)

Answer: (3)

JEE Main 2026 (Online) 23rd January Morning Shift

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2

For the given logic gate circuit, which of the following is the correct truth table? [figure]

  1. arrayccc n & m & z \ 0 & 0 & 1 \ 0 & 1 & 1 \ 1 & 1 & 0 \ 1 & 0 & 0 array
  2. arrayccc n & m & z \ 0 & 0 & 1 \ 0 & 1 & 0 \ 1 & 1 & 1 \ 1 & 0 & 0 array
  3. arrayccc n & m & z \ 0 & 0 & 0 \ 0 & 1 & 1 \ 1 & 1 & 0 \ 1 & 0 & 1 array
  4. arrayccc n & m & z \ 0 & 0 & 1 \ 0 & 1 & 0 \ 1 & 1 & 0 \ 1 & 0 & 0 array
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3

Find the correct combination of A, B, C and D inputs which can cause the LED to glow. [figure]

  1. 1000
  2. 0011
  3. 0100
  4. 1101
JEE Main 2026 (Online) 22nd January Morning Shift
4

The correct truth table for the given input data of the following logic gate is : [figure]

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
JEE Main 2026 (Online) 22nd January Evening Shift
5

The given circuit works as : [figure]

  1. NOR gate
  2. OR gate
  3. AND gate
  4. NAND gate
JEE Main 2026 (Online) 21st January Morning Shift
6

The charge stored by the capacitor C in the given circuit in the steady state is . [figure]

  1. 7.5
  2. 5
  3. 10
  4. 12.5
JEE Main 2026 (Online) 21st January Evening Shift
7

The output voltage in the following circuit is (Consider ideal diode case) [figure]

  1. 0 V
  2. +5 V
  3. −5 V
  4. 10 V
JEE Main 2025 (Online) 8th April Evening Shift
8

In the following circuit, the reading of the ammeter will be (Take Zener breakdown voltage = 4 V) [figure]

  1. 60 mA
  2. 80 mA
  3. 10 mA
  4. 24 mA
JEE Main 2025 (Online) 7th April Morning Shift
9

Consider the following logic circuit. [figure] The output is Y = 0 when :

  1. A = 1 and B = 0
  2. A = 0 and B = 0
  3. A = 1 and B = 1
  4. A = 0 and B = 1
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10

The Boolean expression Y = A BC + A C can be realised with which of the following gate configurations. Choose the correct answer from the options given below:

  1. B, C Only
  2. A, B, C Only
  3. A, B Only
  4. A, C Only
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11

Consider an n-type semiconductor in which ne and nh are number of electrons and holes, respectively. Choose the correct answer from the options given below :

  1. (A), (B), (E) only
  2. (A), (C), (E) only
  3. (A), (B), (C) only
  4. (A), (C), (D) only
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