Question 1
Damped oscillations are those oscillations which ___________ continuously with time.
A. Increasing
B. Decreasing
C. Increasing or decreasing
D. Neither increasing nor decreasing
View Answer
Answer: Option C
Explanation:
Damped oscillations are those oscillations which decrease or increases continuously with time.
Question 2
Frequency of oscillation of alternator is ___________
A. 100Hz
B. 50Hz
C. 1KHz
D. 200Hz
View Answer
Answer: Option B
Explanation:
Alternator frequency depends upon the speed of rotation and the number of pairs of rotor poles. When connected to a power system, alternators are synchronized with the grid frequencies which is either 50/60Hz depending on the geographical location.
Question 3
High frequency oscillators have a frequency range of ___________
A. 300K Hz-2G Hz
B. 100k Hz-500k Hz
C. 8k Hz-800K Hz
D. 4K Hz-1G Hz
View Answer
Answer: Option A
Explanation:
High frequency oscillators are also called Radio frequency oscillators. It has a range of 300KHz to several megahertz.
Question 4
If oscillation amplitude increases continuously it is called ___________
A. Overdamped
B. Underdamped
C. Sustained
D. No specific name
View Answer
Answer: Option A
Explanation:
If oscillation amplitude increases continuously it is called overdamped oscillation.
Question 5
Low frequency oscillators have a frequency range of ___________
A. 20 Hz-20K Hz
B. 20 Hz -100k Hz
C. 1 Hz -20k Hz
D. 50 Hz -100k Hz
View Answer
Answer: Option B
Explanation:
Low frequency oscillators are also called Audio frequency oscillators. It operates in low frequencies, that is from 20Hz to 100-200KHz.
Question 6
Mark-to-space ratio is related with ___________
A. Saw-tooth generator
B. LC oscillator
C. RC oscillator
D. Crystal oscillator
View Answer
Answer: Option A
Explanation:
MSR or Mark-to-space ratio is related with saw-tooth generator. It is the ratio of width of pulse to time between pulses.
Question 7
Oscillation can be classified as damped and sustained on the basis of varying.
A. Input power
B. Frequency
C. Amplitude
D. Noise margin
View Answer
Answer: Option C
Explanation:
Oscillation can be classified as damped and sustained on the basis of varying amplitude.
Question 8
Relaxation oscillators are also known as ___________
A. Multivibrator
B. Phase shift oscillators
C. Blocking oscillators
D. Saw tooth generator
View Answer
Answer: Option A
Explanation:
Relaxation oscillators are also called multivibrators.
Question 9
The inverse of pulse repetition time gives _____________
A. PRF
B. PRT
C. MSR
D. PSR
View Answer
Answer: Option A
Explanation:
The inverse of pulse repetition time gives the PRF- pulse repetition frequency. MSR means mark to space ratio, PRT means power repetition time, PSR is power supply rejection.
Question 10
The ratio of width of pulse to time between pulses are called ___________
A. PSRR
B. PSR
C. MSR
D. CMRR
View Answer
Answer: Option C
Explanation:
The ratio of the width of pulse to time between pulses is called MSR (Mark-to-Space ratio). Other abbreviation denotes PSRR (Power Supply Rejection Ratio), PSR (Power Supply Rejection), CMRR (Common Mode Rejection Ratio).
Question 11
The sinusoidal oscillator is also called ___________
A. LC oscillator
B. Harmonic oscillator
C. RC oscillator
D. Crystal oscillators
View Answer
Answer: Option B
Explanation:
Sinusoidal oscillators are called harmonic oscillators.
Question 12
The time between one pulse to another is known as ___________
A. MSR
B. PRF
C. Time delay
D. PRT
View Answer
Answer: Option D
Explanation:
The time between one pulse to another is known as PRT (Power Repetition Time), other abbreviations denote PRF (Power Repetition Frequency), MSR (Mark-to-Space ratio).
Question 13
Which of the following is not an example of non-sinusoidal oscillator?
A. Sawtooth Generators
B. Blocking oscillators
C. Multivibrator
D. Crystal oscillators
View Answer
Answer: Option D
Explanation:
The sawtooth generator generates an output resembling the teeth of a plain toothed saw. A blocking oscillator is a free running generator, used to produce narrow trigger pulses. A multivibrator is used to produce an output varying between 2 states- a high and low, producing square waves of a different duty cycle. A crystal oscillator is the only one of all used to produce sinusoidal signals.
Question 14
Which of the following is not an example of sinusoidal oscillator?
A. RC phase shift oscillator
B. Weinbridge oscillator
C. Crystal oscillator
D. Blocking oscillator
View Answer
Answer: Option D
Explanation:
A blocking oscillator is a non-sinusoidal oscillator. It produces a free running signal-square shaped and requires only a resistor, transformer and one amplifying element to work. The transistor is blocked off for most of the duty cycle, producing periodic pulses.
Question 15
Which of the following is not an LC oscillator?
A. Hartley Oscillator
B. Colpitts oscillator
C. Crystal oscillator
D. Clapp oscillator
View Answer
Answer: Option C
Explanation:
Crystal oscillator is not an LC oscillator because it does not contain any L or C.
Question 16
Which of the following oscillator cannot be used in low frequency oscillations?
A. Wein bridge oscillators
B. RC phase shift oscillators
C. Colpitts oscillators
D. RC oscillators
View Answer
Answer: Option C
Explanation:
Since Colpitts oscillator is an LC oscillator it cannot be used as a low frequency oscillator. Capacitor present provides a low reactance path to HF signals and thus provides excellent performance in the high frequency region, even in microwave.
Question 17
Which of the following oscillator is not using a feedback network for its oscillation?
A. LC oscillator
B. RC oscillator
C. Crystal oscillator
D. Relaxation oscillators
View Answer
Answer: Option D
Explanation:
UJT relaxation oscillator doesn’t have a feedback system for oscillation.
Question 18
Which of the following oscillator is will give the most stable output oscillation frequency?
A. Colpitts oscillator
B. Clapp oscillator
C. Wein bridge oscillator
D. Crystal oscillator
View Answer
Answer: Option D
Explanation:
Crystal oscillator gives the most stable oscillation. It is the only one not consisting of R, L, C elements and does not deteriorate over time easily. It provides high stability and precision over a range of frequencies.