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What is the cause of harmonic distortion in a power amplifier?

A

Exact replication of output signal

B

Perfectly synced harmonics

C

Non-linearity of transistors

D

Linearity of transistors

Correct Answer: Non-linearity of transistors

Harmonic distortion in a power amplifier is caused due to the non-linearity of transistor devices. Transistors are the active elements in the circuit and are used for amplification. However, they do not equally amplify each point of the input wave form which then creates distortion.

What is the total harmonic distortion if the amplitude of first harmonic distortion is 20dB and second harmonic distortion 25dB?

A

1.2

B

1.52

C

1.25

D

1.5

What is the total harmonic distortion if the amplitude of first harmonic distortion is 20dB, second harmonic distortion 25dB and external noise is 10dB?

A

11.2dB

B

11.52dB

C

11.25dB

D

11.5dB

Power delivered to load calculated by five-point method can be equal to __________ (Pac is power delivered to load without distortion and D is the RMS of all Harmonic distortion)

A

Pac (1-D2)

B

Pac/D2

C

Pac (1+D2)

D

Pac D2

If D1, D2, D3, D4 are the distortion produced by second, third, fourth, fifth respectively (others are insignificant). Then total harmonic distortion is __________

A

√(D12+D22+D32+D42)

B

√(D12+D32)

C

√(D22+D42)

D

√(D12+D22)

If the output power of an amplifier is 10 V, and the input power supplied to the amplifier is 0.229 V given that the DC voltage used is 38.5 V, efficiency of the power amplifier is:

A

25%

B

50%

C

75%

D

35%

Calculate the harmonic distortion component for an output signal having a fundamental amplitude of 3 V and a second harmonic amplitude of 0.25 V.

A

3.83%

B

38.3%

C

83.3%

D

8.33%

A harmonic function is analytic if it satisfies the Laplace equation. If u(x, y) = 2x² - 2y² + 4xy is a harmonic function, then its conjugate harmonic function v(x, y) is

A

4y<sup>2</sup> - 4xy + constant

B

-4xy + 2y<sup>2</sup> - 2x<sup>2</sup> + constant

C

2x<sup>2</sup> - 2y<sup>2</sup> + xy + constant

D

4xy - 2x<sup>2</sup> + 2y<sup>2</sup> + constant

Consider the following provision in Section 300 of the Indian Penal Code:
Several culpable states of mind are referred to with the:
1. intention to cause death
2. knowledge that the act is so imminently dangerous that it must in all probability cause death
3. intention to cause such bodily injury as the offender know to be likely to cause death of the person to whom harm is caused
4. intention of causing such bodily injury as is sufficient in ordinary course of nature to cause death.
The correct order of the sequence in which they are placed in the provision is:

A

1, 2, 3, 4

B

1, 3, 4, 2

C

1, 4, 3, 2

D

2, 3, 4, 1

Consider the amplifier below for the case VDD = 5 V, RD = 24 kΩ, (W/L) = 1 mA/V2, and Vt = 1 V. For amplifier biased to operate with an overdrive voltage of 0.5V, and disregarding the distortion caused by the MOSFET’s square-law characteristic, what is the largest amplitude of a sine-wave voltage signal that can be applied at the input while the transistor remains in saturation?

A

1.61 V

B

1.5 V

C

0.11 V

D

3.11 V

An amplifier using an opamp with slew rate SR=1v/sec has a gain of 40db.If this amplifier has to faithfully amplify sinusoidal signals from dc to 20KHz without introducing any slew-rate induced distortion, then the input signal level exceed

A

795mV

B

395mV

C

795mV

D

39.5mV