Work, Power and EnergyHard
Question
When a metal surface is illuminated by light of wavelengths 400 nm and 250 nm, the maximum velocities of the photoelectrons ejected are v and 2v respectively. The work function of the metal is (h = Planck′s constant, c = velocity of light in air)
Options
A.2 hc × 106 J
B.1.5 hc × 106 J
C.hc × 106 J
D.0.5 hc × 106 J
Solution
By using 
= W0 + 
mv2
⇒
= W0 + 
mv2 .....(i)
and
= W0 + 
m(2v)2 .....(ii)
On solving (i) and (ii)
mv2 = 
.....(iii)
From equation (i) and (iii) W0 = 2hc × 106 J
= W0 + mv2 ⇒
= W0 + mv2 .....(i)and
= W0 + m(2v)2 .....(ii)On solving (i) and (ii)
mv2 = .....(iii)From equation (i) and (iii) W0 = 2hc × 106 J
Create a free account to view solution
View Solution FreeMore Work, Power and Energy Questions
The velocity of a particle of mass of 1 kg changes from 2 m/s north to 2 m/s east in 2 sec. The change in momentum of th...An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii re, r...A body is moved along a straight line by a machine delivering a constant power. The distance moved by the body in time t...Given below are two statements :Statement I: For a mechanical system of many particles total kinetic energy is the sum o...Which one of the following is true ?...