Calculate the number of photons of wavelength 6.63 mm emerging every second from a maser whose output is `6 xx10^-8 W`.

Calculate the energy of a photon of frequency 6.2 xx.10^14 Hz .

The number of photons falling per second on a completely darkened plate to produce a force of 6.62xx10^-5N is 'n'. If the wavelength of the light falling is 5xx10^-7 m, then n= __________ xx10^22. (h=6.62 xx10^-34 J-s )

A current of 0.2 A passes through a metal wire for 20 seconds. Calculate the number of electrons passing through the cross section of the wire during this time. (The charge on an electron = 1.6 times 10^(-19) C)

Calculate the de Broglie wavelength associated with an electron moving with a speed of 6xx10^5 m//s

Calculate the wavelength, frequency and wave number of a light wave whoce periods is 2.0 xx 10^-10 s .

Calculate the number of moles and molecules of sulphur dioxide obtained by combustion of 6.4 xx 10^-2 kg of sulphur (S=32 , O= 16)

Calculate the velocity of sound in gas in which two waves of wavelengths 50 cm and 50.5 cm produce 6 beats per second.

Calculate the wavelength (in nm) associated with a proton moving at 1.0 xx 10^3 m s^-1 .(Mass of proton = 1.67 xx 10^-27 kg and h = 6.63 xx 10^-34J s ).

Calculate the value of Bohr Magneton (Given: Charge on electron = 1.6xx10^-19 C, h (Planck's) constant = 6.63xx10^-34Js, mass of electron m_e = 9.1xx10^-31 kg)