A whistle revolves in a circle with angular speed $$\omega $$ = 20 rad/s using a string of length 50 cm. If the frequency of sound from the whistle is 385 Hz, then what is the minimum frequency heard by an observer which is far away from the centre (velocity of sound $$=$$ 340 m/s)

The equation of a wave is represented by

y $$=$$ 10^$$-$$4 sin(100t $$-$$ $${x \over {10}}$$) m. then the velocity of wave will be

If the tension and diameter of a sonometer wire of fundamental frequency n is doubled and density is halved then its fundamental frequency will become

Two waves having equation x₁ = $$a$$sin($$\omega $$t $$-$$ kx + $$\phi $$₁), x₂ = asin($$\omega $$t $$-$$kx + $$\phi $$₂). If in the resultant wave the frequency and amplitude remain equal to amplitude of superimposing waves, the phase difference between them is