Semiconductor Electronics

Two statements are given below : Choose the correct answer from the options given below :

1. Both Statements A and B are true
2. Both Statements A and B are false
3. Statement A is true, but Statement B is false
4. Statement A is false, but Statement B is true

In the circuit shown below, the voltage appearing across the diode D will be of the form : [figure]

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

The current I in the circuit shown below is : (All diodes are ideal and identical) [figure]

1. 13 A
2. 152 A
3. 53 A
4. 59 A

An ideal Zener diode with breakdown voltage of -3 V is reverse biased with a negative input voltage Vi = -5 V. The magnitude of voltage difference between point B and A is: [figure]

1. 0 V
2. 3 V
3. 2 V
4. 1 V

Three identical p-n junction diodes D1, D2, and D3 are connected across a battery as shown in the figure. If the width of the depletion regions of D1, D2 and D3 are W1, W2 and W3, respectively, then the correct option is: [figure]

1. W2 > W1 = W3
2. W1 > W2 > W3
3. W3 = W1 > W2
4. W3 > W2 > W1

A full wave rectifier circuit with diodes (D1) and (D2) is shown in the figure. If input supply voltage Vin = 220 (100 t) volt, then at t = 15 msec [figure]

1. D1 and D2 both are forward biased
2. D1 and D2 both are reverse biased
3. D1 is forward biased, D2 is reverse biased
4. D1 is reverse biased, D2 is forward biased.

The output (Y) of the given logic implementation is similar to the output of an/a gate. [figure]

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

A logic circuit provides the output Y as per the following truth table : [figure] The expression of the output Y is :

1. A B + A
2. A B + A
3. B
4. B

Consider the following statements A and B and identify the correct answer : [figure]

1. A is correct but B is incorrect
2. A is incorrect but B is correct
3. Both A and B are correct
4. Both A and B are incorrect

The output (Y) of the given logic gate is similar to the output of an/a [figure]

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

[figure] The I-V characteristics shown above are exhibited by a

1. Light emitting diode
2. Zener diode
3. Photodiode
4. Solar cell

When the output of an OR gate is applied as input to a NOT gate, then the combination acts as a

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

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

1. A B
2. A B
3. A + B
4. A + B

Given below are two statements: In the light of the above statements, choose the most appropriate answer from the options given below :

1. Both Statement I and Statement II are incorrect.
2. Statement I is correct but Statement II is incorrect.
3. Statement I is incorrect but Statement II is correct.
4. Both Statement I and Statement II are correct.

A full wave rectifier circuit consists of two p-n junction diodes, a centre-tapped transformer, capacitor and a load resistance. Which of these components removes the ac ripple from the rectified output?

1. p-n junction diodes
2. Capacitor
3. Load resistance
4. A centre-tapped transformer

For the following logic circuit, the truth table is: [figure]

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

[figure] In the given circuits (a), (b) and (c), the potential drop across the two p-n junctions are equal in

1. Circuit (a) only
2. Circuit (b) only
3. Circuit (c) only
4. Both circuits (a) and (c)

In half wave rectification, if the input frequency is 60 Hz, then the output frequency would be

1. Zero
2. 30 Hz
3. 60 Hz
4. 120 Hz

[figure] The truth table for the given logic circuit is

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

[figure] Identify the equivalent logic gate represented by the given circuit

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

The incorrect statement about the property of a Zener diode is :

1. p and n regions of Zener diode are heavily doped
2. Zener voltage remains constant at breakdown
3. It is designed to operate under reverse bias
4. Depletion region formed is very wide

The collector current in a common base amplifier using n-p-n transistor is 24 mA. If 80% of the electrons released by the emitter is accepted by the collector, then the base current is numerically :

1. 3 mA and entering the base
2. 6 mA and leaving the base
3. 3 mA and leaving the base
4. 6 mA and entering the base

Consider the following statements (A) and (B) and identify the correct answer. (A) A Zener diode is connected in reverse bias, when used as a voltage regulator. (B) The potential barrier of p-n junction lies between 0.1 V to 0.3 V.

1. (A) is incorrect but (B) is correct.
2. (A) and (B) both are correct.
3. (A) and (B) both are incorrect.
4. (A) is correct and (B) is incorrect.

The electron concentration in an n-type semiconductor is the same as hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.

1. No current will flow in p-type, current will only flow in n-type
2. Current in n-type = current in p-type
3. current in p-type > current in n-type
4. current in n-type > current in p-type

For the given circuit, the input digital signals are applied at the terminals A, B and C. What would be the output at the terminal y? [figure]

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

The increase in the width of the depletion region in a p-n junction diode is due to :

1. reverse bias only
2. both forward bias and reverse bias
3. increase in forward current
4. forward bias only

For the logic circuit shown, the truth table is : [figure]

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

For transistor action, which of the following statements is correct?

1. Base, emitter and collector regions should have same size.
2. Both emitter junction as well as the collector junction are forward biased.
3. The base region must be very thin and lightly doped.
4. Base, emitter and collector regions should have same doping concentrations.

The correct Boolean operation represented by the circuit diagram drawn is : [figure]

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

For a p-type semiconductor, which of the following statements is true?

1. Holes are the majority carriers and trivalent atoms are the dopants.
2. Holes are the majority carriers and pentavalent atoms are the dopants.
3. Electrons are the majority carriers and pentavalent atoms are the dopants.
4. Electrons are the majority carriers and trivalent atoms are the dopants.