Question

Calculate the frequency of the waveform v(t) = sin(πt+π÷4) + sin(πt+π÷74) + sin(πt+π÷56).

(a) .1 Hz

(b) .8 Hz

(c) .5 Hz

(d) .2 Hz

I have been asked this question during an interview.

My question comes from Solar Powered Vehicles topic in chapter Solar and Battery Powered Drives of Electric Drives

Answer 1

The correct choice is (c) .5 Hz

To explain I would say: The fundamental time period of the sine wave is 2π. The time period of i(t) is L.C.M {2,2,2}=2 sec. The frequency of the waveform is 1/2=.5 Hz. The time period is independent of phase shifting and time-shifting.