Semiconductor Electronics

The output Y for the given inputs A and B to the circuit is : [figure]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The maximum rated power of the LED is 2 mW and it is used in the circuit with input voltage of 5 V as shown in the figure below. The current through resistance RS is 0.5 mA. The minimum value of the resistance of RS, to ensure that the LED is not damaged is k . [figure]

1. 6
2. 2
3. 4
4. 5

Refer to the logic circuit given below. For two inputs (A=1, B=1) and (A=0, B=1), output (Y) will be . [figure]

1. 1, 0 respectively
2. 0, 1 respectively
3. 0, 0 respectively
4. 1, 1 respectively

For the given logic circuit, which of the following inputs combination will make both LED-1 and LED-2 to glow? [figure]

1. A = 0, B = 1, C = 1
2. A = 1, B = 0, C = 0
3. A = 1, B = 0, C = 1
4. A = 1, B = 1, C = 0

In a semiconductor p-n diode, the doping concentrations on p-side and n-side are 1015 atoms/cm3 and 1018 atoms/cm3, respectively. Which one of the following statements is true ?

1. Widths of depletion region on either side of the interface are equal
2. The depletion region width is more on p-side compared to that in n-side
3. The depletion region width is more on n-side compared to that in p-side
4. No depletion region forms because of unequal doping concentrations on p and n-sides

Two 4 bits binary numbers, A = 1101 and B = 1010 are given in the inputs of a logic circuit shown in figure below. The output (Y) will be : [figure]

1. Y = 1101
2. Y = 0010
3. Y = 0111
4. Y = 1000

Consider a circuit consisting of a capacitor (20 μF), resistor (100 Ω) and two identical diodes as shown in figure. The resistance of diode under forward biasing condition is 10 Ω. The time constant of the circuit is 10-3 s. The value of is . [figure]

1. 2.2
2. 2.0
3. 2.1
4. 2.4

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Choose the correct answer from the options given below :

1. Both (A) and (R) are true and (R) is the correct explanation of (A)
2. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
3. (A) is true but (R) is false
4. (A) is false but (R) is true

A diode has Zener voltage of 10 V and maximum power dissipation of 0.5 W, then the minimum resistance to be used in series with this diode for safety when it is connected to a 25 V power supply is Ω.

For the given circuit (shown in part (A)) the time dependent input voltage vin(t) and corresponding output vo(t) are shown in part (B) and part (C), respectively. Identify the components that are used in the circuit between points X and Y. [figure]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

If X and Y are the inputs, the given circuit works as . [figure]

1. OR gate
2. AND gate
3. NAND gate
4. NOR gate

Assuming in forward bias condition there is a voltage drop of 0.7 V across a silicon diode, the current through diode D1 in the circuit is mA. (Assume all diodes in the given circuit are identical) [figure]

1. 17.6
2. 18.8
3. 20.15
4. 11.7

Two p-n junction diodes D1 and D2 are connected as shown in figure. A and B are input signals and C is the output. The given circuit will function as a . [figure]

1. AND Gate
2. OR Gate
3. NOR Gate
4. NAND Gate

A voltage regulating circuit consisting of Zener diode, having breakdown voltage of 10 V and maximum power dissipation of 0.4 W, is operated at 15 V. The approximate value of protective resistance in this circuit is .

Identify the correct truth table of the given logic circuit. [figure]

1. arrayccc A & B & Y \ 0 & 0 & 0 \ 0 & 1 & 0 \ 1 & 0 & 1 \ 1 & 1 & 0 array
2. arrayccc A & B & Y \ 0 & 0 & 0 \ 0 & 1 & 1 \ 1 & 0 & 1 \ 1 & 1 & 0 array
3. arrayccc A & B & Y \ 0 & 0 & 1 \ 0 & 1 & 1 \ 1 & 0 & 1 \ 1 & 1 & 0 array
4. arrayccc A & B & Y \ 0 & 0 & 1 \ 0 & 1 & 0 \ 1 & 0 & 1 \ 1 & 1 & 0 array

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

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

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

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

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The given circuit works as : [figure]

1. NOR gate
2. OR gate
3. AND gate
4. NAND gate

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

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

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

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

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

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

Choose the correct logic circuit for the given truth table having inputs A and B. [figure]

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The truth table corresponding to the circuit given below is: [figure]

1. arrayccc A & B & C \ 0 & 0 & 0 \ 0 & 1 & 0 \ 1 & 0 & 1 \ 1 & 1 & 1 array
2. arrayccc A & B & C \ 0 & 0 & 1 \ 1 & 0 & 0 \ 0 & 1 & 0 \ 1 & 1 & 0 array
3. arrayccc A & B & C \ 0 & 0 & 1 \ 0 & 1 & 0 \ 1 & 0 & 0 \ 1 & 1 & 0 array
4. arrayccc A & B & C \ 0 & 0 & 0 \ 1 & 0 & 0 \ 0 & 1 & 0 \ 1 & 1 & 1 array

A zener diode with 5 V zener voltage is used to regulate an unregulated dc voltage input of 25 V. For a 400 resistor connected in series, the zener current is found to be 4 times load current. The load current (IL) and load resistance (RL) are :

1. IL = 0.02 mA; RL = 250
2. IL = 10 A; RL = 0.5
3. IL = 10 mA; RL = 500
4. IL = 20 mA; RL = 250

In the digital circuit shown in the figure, for the given inputs the P and Q values are : [figure]

1. P = 0, Q = 1
2. P = 1, Q = 0
3. P = 0, Q = 0
4. P = 1, Q = 1