Maximum kinetic energy of photon is '$$E$$' when wavelength of incident radiation is '$$\lambda$$'. If wavelength of incident radiations is reduced to $$\frac{\lambda}{3}$$ then energy of photon becomes four times. Then work function of the metal is

Consider the Doppler effect in two cases. In the first case, an observer moves towards a stationary source of sound with a speed of $$50 \mathrm{~m} / \mathrm{s}$$. In the second case, the observer is at rest and the source moves towards the observer with the same speed of $$50 \mathrm{~m} / \mathrm{s}$$. Then the frequency heard by the observer will be

[velocity of sound in air $$=330 \mathrm{~m} / \mathrm{s}$$.]

According to Curie's law in magnetism, the correct relation is ( $$\mathrm{M}=$$ magnetization in paramagnetic sample, $$\mathrm{B}=$$ applied magnetic field, $$\mathrm{T}=$$ absolute temperature of the material, $$\mathrm{C}=$$ curie's constant)

A double convex air bubble in water behaves as