Question

In an experiment to obtain Lissajous’ figures, one tuning fork is of 250 Hz and a circular figure occurs after five seconds. What deductions may be made about the frequency of the other tuning fork?

Answer 1

The Lissajous’ figures are repeated in 5s i.e. the second tuning fork gains or loses one vibration over the first one in 5s. Thus, the difference in frequencies = 1/5 = 0.2 Hz. Hence, the possible frequencies of the second tuning fork are (250 + 0.2) = 250.2 Hz or (250 – 0.2) = 249.8 Hz.