Noise: Is an unwanted sound that is unpleasant, loud, or disruptive

This is an MCQ-based quiz on Noise.

This includes Bandpass filter, Bandstop filter,  Low pass filter, High pass filter, Shot noise, Partition noise, Industrial noise, and Flicker noise.

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Which occurs due to equilibrium fluctuations?

Thermal noise Johnson noise Thermal & Johnson noise None of the mentioned

In PWM signal reception, the Schmitt trigger circuit is used

To remove noise To produce ramp signal For synchronization None of the above

Shot noise is

Stochastic process Poisson process Stochastic & Poisson process None of the mentioned

Flicker noise is called as

White noise Pink noise Brown noise None of the mentioned

Shot noise is avoidable when current is

Zero One Infinity None of the mentioned

Which has the same power spectral density?

White noise Brown noise White & Brown noise None of the mentioned

Shot noise is produced by

Electrons Photons Electrons & Photons None of the mentioned

Two functions are called as orthogonal if on integrating the product we get

One Zero Infinity None of the mentioned

Which offers better SQNR?

Delta modulation PCM Delta modulation & PCM None of the mentioned

SQNR can be improved by _______ sampling rate.

Increasing Decreasing Does not depend None of the mentioned

Low frequency noise is

Transit time noise Flicker noise Shot noise None of the above

Noise power at the resistor is affected by the value of the resistor as

Directly proportional to the value of the resistor Inversely proportional to the value of the resistor Unaffected by the value of the resistor Becomes half as the resistance value is doubled

Noise is added to a signal in a communication system

At the receiving end At transmitting antenna In the channel During regeneration of the information

Notch filter is a

Band pass filter Band stop filter Low pass filter High pass filter

For a two stage amplifier, first amplifier has Voltage gain = 20, Input Resistance Rin1=700Ω, equivalent Resistance Req1=1800Ω and Output Resistor Ro1 = 30KΩ. The corresponding values of second amplifier are : 25, 80 KΩ, 12 KΩ, 1.2 MΩ respectively. What is the value of equivalent input noise resistance of the given two stage amplifier?

2609.1Ω 2607.1Ω 107.1Ω 2107.1Ω

The Noise Factor for cascaded amplifiers (FN) is given by (F1, F2, F3 .. FN, G1, G2, G3….GN) are the noise factors and the gains of the amplifiers at different stages:

FN = F1 + F2/ G1 + F3/ G1G2+ ..+ FN/ G1G2G3GN FN = F1 + (F2 – 1)/ G1 + (F3 – 1)/ (G1+G2)+ ..+(FN – 1)/ (G1+G2+G3+…+GN) FN = F1 + F2/ G1 + F3/ (G1+G2) +…+ FN/ (G1+G2+G3+…+GN) FN = F1 + (F2 – 1)/ G1 + (F3 – 1)/ G1G2+…+(FN – 1)/ G1G2G3GN

Noise Factor(F) and Noise Figure(NF) are related as

NF = 10 log10(F) F = 10 log10(NF) NF = 10 (F) F = 10 (NF)

Noise factor for a system is defined as the ratio of

Input noise power (Pni) to output noise power (Pno) Output noise power (Pno) to input noise power (Pni) Output noise power (Pno) to input signal power (Psi) Output signal power (Pso) to input noise power (Pni)

In Hilbert transform of a signal, the phase angles of all components of a given signal are shifted by

+/- π +/- π/4 +/- π/2 Any angle from 0 to 360 degree

The noise voltage (Vn) and the signal bandwidth (B) are related as

Vn is directly proportional to bandwidth Vn is directly proportional to √bandwidth Vn is inversely proportional to absolute temperature Vn is inversely proportional to bandwidth
Quiz/Test Summary
Title: Noise: Is an unwanted sound that is unpleasant, loud, or disruptive
Questions: 20
Contributed by:
Diego