Electronics MCQs for CSIR NET, GATE Physics (Assignment 2) - ChemContent

This article contains a quiz with 10 MCQs from Physics chapter "Electronics".

• Total Marks = 40
• Correct Answer = +4 Marks
• Incorrect Answer = -1 Marks

Mathematical Physics Practice Test 1

Question 1.

In a transistor, the change in base current from 100 µA to 125 µA causes a change in collector current from 5 mA to 7.5 mA, keeping collector-to-emitter voltage constant at 10 V. What is the current gain of the transistor?

(1) 200

(2) 100

(3) 50

(4) 25

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Question 2.

A transistor operating in a common base configuration has a forward current gain factor, α =0.99. If the emitter current changed by 1 mA then the change in the base current will be

(1) 100 µA

(2) 0.01 mA

(3) 0.99 mA

(4) 99 mA

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Question 3.

A common base amplifier uses n-p-n transistor. When the transistor is biased in the active region, which one of the following statements is correct?

(1) Emitter and collector are both reverse biased

(2) Emitter and collector are both forward biased

(3) Emitter is forward biased and collector is reverse biased

(4) Emitter is reverse biased and collector is forward biased

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Question 4.

In the transistor circuit given below, the base current is 35 µA. What is the value of the base resister R_b?

(1) 200 kΩ

(2) 157 kΩ

(3) 337 kΩ

(4) 257 kΩ

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Question 5.

Match List I with List II, in respect of a BJT connected in the CE configuration and select the correct answer using the codes given below the Lists.

A, B, C, D match to

(1) 3, 4, 5, 2

(2) 5, 4, 2, 3

(3) 5, 3, 2, 4

(4) 4, 2, 1, 3

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Question 6.

For a BJT, the current amplification factor α = 0.9. This transistor is connected in CE configuration. When the base current changes by 0.4 mA, the change in collector current will be

(1) 36 mA

(2) 9 mA

(3) 4 mA

(4) 3.6 mA

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Question 7.

In CE mode, the input characteristics of a BJT is the variation of

(1) I_B varsus V_BE at constant V_CE

(2) I_C versus V_CE at constant V_BE

(3) I_C versus V_CE at constant I_B

(4) I_B versus V_CE at constant V_BE

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Question 8.

Which one of the following is correct? The common base configuration of a transistor is characterized by

(1) low voltage gain, high current gain

(2) low input resistance, high output resistance

(3) high voltage gain, low output resistance

(4) low current gain, low input resistance

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Question 9.

The Effect Transistor (FET) is a

(1) current controlled device

(2) voltage controlled device

(3) both current and voltage controlled device

(4) neither current controlled nor voltage controlled device.

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Question 10.

Under normal operating conditions, the gate terminals of an n-channel Junction Field Effect Transistor (JEET) and an n-channel Metal oxide Semiconductor Field Effect Transistor (MOSFET) are

(1) both biased with positive potentials

(2) both biased with negative potentials

(3) biased with positive and negative potentials respectively.

(4) biased with negative and positive potential respectively.

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Question 11.

The high input impedance of Field Effect Transistor (FET) amplifier is due to

(1) the pinch-off voltage

(2) its very low gate current

(3) the source and drain being apart

(4) the geometry of the FET

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Question 12.

A n-channel silicon (dielectric constant = 12) FET with a channel width a = 2 × 10⁶ m is doped with 10²¹ electron/m³. The pinch-off voltage is

(1) 0.86 V

(2) 0.68 V

(3) 8.6 V

(4) 6.8 V

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Question 13.

A field effect transistor is a

(1) unipolar device

(2) special type of bipolar junction transistor

(3) unijunction device

(4) device with low input impedance

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Question 14.

A junction field effect transistor behaves as a

(1) voltage controlled current source

(2) voltage controlled voltage source

(3) current controlled voltage source

(4) current controlled current source

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Question 15.

The correct symbol for an N-channel Junction field Effect Transistor (JEET) is

(1) 

(2) 

(3) 

(4) 

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Question 16.

The JEET is

(1) a unipolar device

(2) a voltage controlled device

(3) a current controlled device

(4) both (1) and (2)

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Question 17.

A JEET always operates with

(1) the gate to source p-n junction reverse biased

(2) the gate to source p-n junction forward biased

(3) the drain connected to ground

(4) the gate connected to the source

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Question 18.

In certain FET, circuit, V_GS = 0 V, V_DD = 15V, V_DSS = 15 mA and R_D = 470 Ω. If R_D is decreased to 330 Ω, I_DSS is

(1) 19.5 mA

(2) 10.5 mA

(3) 15 mA

(4) 1 mA

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Question 19.

At cut-off, the JEET channel is

(1) as its widest point

(2) completely closed by the depletion region

(3) extremely narrow

(4) reverse biased

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Question 20.

A certain JEET date sheet gives V_GS(OFF) = – 4V. The pinch off voltage, V_P

(1) cannot be determined

(2) is – 4V

(3) depends on V_GS

(4) is + 4V

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Answer Key

q1: 'b', q2: 'd', q3: 'c', q4: 'd', q5: 'b',  q6: 'd', q7: 'b', q8: 'c', q9: 'a', q10: 'b',  q11: 'b', q12: 'b', q13: 'a', q14: 'a', q15: 'd', q16: 'd', q17: 'a', q18: 'c', q19: 'b', q20: 'd'

For further questions queries or suggestions, please leave your comments below.