JAMB - Physics (1983 - No. 9)
which of the following is NOT correct? i. the pitch of a sound note depends on the frequency of vibrations. ii. the intensity of a sound note is proportional to the amplitude of vibrations. iii. beats are produced by two sources of sound because one wave is travelling faster than the other. iv. when two sources of sound of frequencies 500Hz and 502Hz are sounded together, a beat frequency of 2Hz is observed. v. the first harmonic of a tone have double the frequency of the fundamental note.
i and ii
ii and iii
i and iii
iii and iv
iv and v
설명
Beats are produced because one wave interferes with another of nearly equal frequency.
The first harmonic is the fundamental frequency itself.
(iii) and (v) are wrong.