Chapter 11
70 Maths Exercise Solutions
Monochromatic light of frequency 
is produced by a laser. The power emitted is 
(a) What is the energy of a photon in the light beam?
(b) How many photons per second, on an average, are emitted by the source?
is produced by a laser. The power emitted is (a) What is the energy of a photon in the light beam?
(b) How many photons per second, on an average, are emitted by the source?
The work function of cesium is 
. Find
The threshold frequency for cesium.
. FindThe threshold frequency for cesium.
The work function of caesium is 
Find
The wavelength of the incident light if the photo current is brought to zero by a stopping potential of
.
FindThe wavelength of the incident light if the photo current is brought to zero by a stopping potential of
.The wavelength of light in the visible region is about 
for violet colour, about 
average wavelength
for yellow-green color and about 
for red colour.
What are the energies of photons in
at the 
violet end, 
average wave length, yellow-green colour, and 
red end of the visible spectrum?
for violet colour, about average wavelength for yellow-green color and about for red colour.What are the energies of photons in
at the violet end, average wave length, yellow-green colour, and red end of the visible spectrum? The wavelength of light in the visible region is about 
for violet colour, about 
average wavelength for yellow-green colour and about 
for red colour.
From which of the photosensitive materials with work functions listed in table and can you build a photoelectric device that operates with visible light?
for violet colour, about average wavelength for yellow-green colour and about for red colour.From which of the photosensitive materials with work functions listed in table and can you build a photoelectric device that operates with visible light?
What is the de Broglie wavelength associated with an electron moving with a speed of 
.
.What is the de Broglie wavelength associated with
a ball of mass,
travelling at 
?
a ball of mass,
travelling at ?An electron, an 
particle, and a proton have the same kinetic energy. Which of these particles has the shortest de Broglie wave length?
particle, and a proton have the same kinetic energy. Which of these particles has the shortest de Broglie wave length?A particle is moving three times as fast as an electron.The ratio of the de Broglie wavelength of the particle to that of theelectron is 
. Calculate the particle’s mass and identify the particle.
. Calculate the particle’s mass and identify the particle.Find the maximum frequency produced by 
electrons.
electrons.Still Have Question?