A bulb emits `2 xx 10^20` photons of wave length 400 nm in one second. Calculate the rate of emission of photons per second.

A 25 watt bulb emits monochromatic yellow light of wavelength of 0.57 mum . Calculate the rate of emissionn of quanta per second.

Calculate the wave length of photon having energy 2'ev.

An 80 watt bulb emits monochromatic light of wavelength 480 nm. Calculate the number of photons emitted per second by the bulb?

A monochromatic source, emitting light of wavelength, 600 nm, has a power output of 66W. Calculate the number of photons emitted by this source is 2 minutes.

The ratio of the power of two sources of light is 2 and the ratio of wavelengths of the emerging monochromatic beam is also 2. What is the ratio of number of photons emitted per second.

The maximum velocities of the photoelectrons ejected are v and 2v for incident light of wavelength 400 nm and 250 nm on a metal surface respectively. Calculate the work function of the metal. Given h = 6.63 xx 10^(-34)J.s and c = 3 xx 10^(8) m.s^(-1)

After the collision of two H atoms each atom emits a photon of wavelength 121.6 nm which transition leads to this wavelength ?how fast were the hydrogen atoms travelling before collision?(Mass of H atom= 1.69xx10^-27 kg)

A bulb emits light of wavelength 4500A^@ .The bulb is rated as 150 watt and 8% of the energy is emitted as light.how many photons are emitted by the bulb per second?

If a reaction with t1//2=69.3 second, has a rate constant value of 10^(-2) per second. Calculate the order of the reaction.