Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
yogesh gandhi Grade: 12

in the photo emissivecell with exicting wavelenght  X , THE MAX. kinetic energy of electron is K . if thr exicting wavelength is change to 3/4X the kinetic energy of the fastest emitted electron will be.....

1. equal to 3/4 k

2. 4/3K

3.  less than K.

4.  more than K.


8 years ago

Answers : (1)

Rajnish Mishra
23 Points


If the light frequency is greater than a threshold frequency, fo, then a photoelectron will be ejected with kinetic energy up to a maximum value, K, according to the linear formula:


Photoelectric Equation is given by: K = hc/λ – W

(where W is the work function of the metal surface, h and c constants)


If the exciting wavelength is changed by ¾ X then the equation for Kmax will be:


Kmax1 =   4hc/3X – W


We can see that the Kmax1 (that is new max kinetic energy of an electron) is greater than Kmax. Hence the kinetic energy of the fastest emitted electron will be more than K.


Answer – 4.




8 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete Physics Course - Class 12
  • OFFERED PRICE: Rs. 2,756
  • View Details
  • Complete Physics Course - Class 11
  • OFFERED PRICE: Rs. 2,968
  • View Details

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details