Test: Classification of Oscillators - Electrical Engineering (EE) MCQ

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.

Damped oscillations are those oscillations which decrease or increases continuously with time.

If oscillation amplitude increases continuously it is called overdamped oscillation.

MSR or Mark-to-space ratio is related with saw-tooth generator. It is the ratio of width of pulse to time between pulses.

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).

Oscillation can be classified as damped and sustained on the basis of varying amplitude.

If the oscillation amplitude decreases continuously it is called underdamped oscillation.

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.

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).

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.