Question

The simultaneous applications of signals x (t) and y (t) to the horizontal and vertical plates respectively, of an oscilloscope, produce a vertical figure of 8 displays. If P and Q are constants and x(t) = P sin (4t + 30), then y(t) is equal to _________

(a) Q sin (4t -30)

(b) Q sin (2t +15)

(c) Q sin (8t +60)

(d) Q sin (4t +30)

The question was posed to me in an online quiz.

The origin of the question is Advanced Miscellaneous Problems on Measurement of Resistance in chapter Measurement of Resistance of Electrical Measurements

Answer 1

Correct answer is (b) Q sin (2t +15)

Explanation: \(\frac{f_y}{f_x} = \frac{x-peak}{y-peak}\)

Here, x-peak = 1 and y-peak = 2

∴ y(t) = Q sin (2t + 15).