A wave passes from one medium to another medium. Mention one property of the wave out of speed, frequency or wavelength (i) which changes, (ii) which does not change.
A wave passes from one medium to another medium. Mention one property of the wave out of speed, frequency or wavelength (i) which changes, (ii) which does not change.

(i) The wavelength (or speed) of a wave varies when it travels from one medium to another.

(ii) The frequency of a wave travelling in one media does not change as it travels through another medium.