Question

Given an intensity versus wavelength graph for the production of X-ray
using an element. How will the graph be if I increase the potential?

• A.
  
• B.
  
• C.
  
• D.
  

Answer 1

The correct option is C


As, the Kinetic energy of an electron is
$K=e{V}_0$, when we increase the accelerating potential of the circuit, the maximum kinetic energy of an electron increases.
Now, We also know that since the cut-off wavelength is given by $\lambda =\frac{hc}{eV}$
If V is increased, $\lambda$ will decrease and hence the cut-off point on the graph will shift leftwards.
Now, let’s talk about what will happen to the intensity of the photons emitted. So once the electron are hitting the anode with higher energy now, an amount of certain energy that it may lose as an x-ray photon in any interaction can be emitted multiple times.
Trv understanding with this analogy : If you have twenty bucks. you can buy a ten rupees pen twice, but if you have hundred bucks, the same ten rupees pen, you may buy now ten times.
Hence we may conclude that the intensity of the photons would increase as well.