A plane wave of sound traveling in air is incident upon a plane surface of a liquid. The angle of incidence is $60^o.$ The speed of sound in air is $300 \,m /s$ and in the liquid it is $600\, m /s .$ Assume Snell’s law to be valid for sound waves.
The wave will refract into liquid away from normal
The wave refract into liquid towards the normal
The wave will reflect back into air
none of these
If the length of stretched string is shortened by $40\%$ and the tension is increased by $44\%$, then the ratio of the final and initial fundamental frequencies is
Fundamental frequency of sonometer wire is $n$. If the length, tension and diameter of wire are tripled, the new fundamental frequency is
Four wires of identical length, diameters and of the same material are stretched on a sonometre wire. If the ratio of their tensions is $1 : 4 : 9 : 16$ then the ratio of their fundamental frequencies are
Two wires are in unison. If the tension in one of the wires is increased by $2\%, 5$ beats are produced per second. The initial frequency of each wire is .... $Hz$
The frequency of transverse vibrations in a stretched string is $200 Hz$. If the tension is increased four times and the length is reduced to one-fourth the original value, the frequency of vibration will be .... $Hz$