Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If K1 and K2 are maximum kinetic energies of photoelectrons emitted when lights of wavelength λ1 and λ2 respectively incident on a metallic surface. If λ1=3λ2, then
PhysicsDual Nature of MatterJEE Main
Options:
  • A K1>K23
  • B K1<K23
  • C K1=3K2
  • D K2=3K1
Solution:
2264 Upvotes Verified Answer
The correct answer is: K1<K23
Eienstein's photoelectric equation is given as,

K1=hc1λ1-1λ0 ...(i)

and K2=hc1λ2-1λ0 ...(ii)

Dividing Equation (i) by Equation (ii), we get

K1K2=1λ1-1λ01λ2-1λ0

Since, λ1=3λ2

K1K2=13λ2-1λ01λ2-1λ0

=13λ2 1-3λ0/λ21λ21-1λ0

K1K2=13 1-3λ0/λ21-1λ0/λ2

3K1K2=1-3/λ0/λ21-1/λ0λ2<1

  3K1K2<1K1<K23

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.