Why a signal transmitted from a TV tower cannot be received beyond a certain distance? Write the expression for the optimum separation between the receiving and the transmitting antenna.

A particle and a proton of the same kinetic energy are in turn allowed to pass through a magnetic field →B, acting normal to the direction of motion of the particles. Calculate the ratio of radii of the circular paths described by them.

State Bohr’s quantization condition of angular momentum. Calculate the shortest wavelength of the Brackett series and state to which part of the electromagnetic spectrum does it belong.

OR

Calculate the orbital period of the electron in the first excited state of hydrogen atom.

Why is wave theory of electromagnetic radiation not able to explain photo electric effect? How does photon picture resolve this problem?

Plot a graph showing variation of de Broglie wavelength (γ) associated with a charged particle of mass m, versus 1/ √V , where V is the potential difference through which the particle is accelerated. How does this graph give us the information regarding the magnitude of the charge of the particle?