If the wavelength of H_α line of the Balmer series of the hydrogen spectum is λ the wavelength of the 

When an electron in the hydrogen atom jumps from the 2nd orbit to the 1st orbit, the wavelength of the radiation emitted is λ. When an electron jumps from 3rd orbit to 1st orbit, the wavelength of emitted radiation would be

Three-fourths of the active nuclei present in a radioactive sample decay in 3/4 s. The half-life of the sample is 

Acceleration of an electron in the first Bohr orbit is proportional to 

The de - Broglie wave corresponding to a particle of mass m and velocity v has a wavelength associated with it is

A radiotransmitter operates at a frequency 1000 kHz and a power of 66 kW. Find the number of photons emitted per second.

Light of wavelength 4000 angstrom is incident on a sodium surface for which the threshold wavelength of photoelectrons is 5420 angstrom. The work function is 

When the atoms in a sample of hydrogen like atoms are in the fourth (n = 4) orbit, how many spectral lines will be emitted in the radiation spectrum of the sample?

Bragg's equation will have no solution, if

When ultraviolet rays are incident on metal plate,the photoelectric effect does not occur.It occurs by incidence of