A laboratory generator is connected to a cathode-ray oscilloscope (CRO) whose time…
PHYSICS · Subjective · CBSE · Physics · Alternating Current · Alternating Current
Problem
A laboratory generator is connected to a cathode-ray oscilloscope (CRO) whose time base is set at 2.0msper division. The trace shows that successive positive zero crossings of the voltage are separated by 4.0 horizontal divisions.
(i) Calculate the frequency of the generator’s output.
(ii) An ac voltmeter connected across the same output reads an rms value of 120V. Determine the corresponding peak voltage.
(iii) For how much total time in each complete cycle does the magnitude of the instantaneous voltage exceed 0.70 times its peak value? Express your answer both in milliseconds and as a percentage of the period.