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 asked by my college director while I was bunking the class.

This key question is from Problems Involving Coupling Coefficient topic in chapter Resonance & Magnetically Coupled Circuit of Network Theory

Answer 1

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

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

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

∴ y(t) = Q sin (2t + 15).