Physics Questions and Answers

The range of wavelengths of the visible spectrum is 400nm - 700nm. The wavelength of gamma rays is

Which of the following statements about defects of vision is/are CORRECT?

i. for a long sighted person, close objects appear blurred.
ii. for a short sighted person, distant objects appear blurred.
iii. short sight is corrected by using a pair of converging lenses.

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.

A ship travelling towards a cliff receives the echo of its whistle after 3.5 seconds. A short while later, it receives the echo after 2.5 seconds. If the speed of sound in air under the prevailing condition is 250ms ^-1, how much closer is the ship to the cliff?

Which of the following statements about liquid pressure is NOT correct? The pressure