A circuit is connected as shown in the figure with the switch S open. When the switch is closed, the total amount of charge that flows from Y to X is

A ray of light travelling in water in incident on its surface open to air. The angle of incidence is $$\theta$$, which is less than the critical angle. Then there will be

In the option given below, let E denote the rest mass energy of a nucleus and n a neutron. The correct option is

The largest wavelength in the ultraviolet region of the hydrogen spectrum is 122 nm. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is