Question

If the accelerating potential in an X-ray is increased:

• lambda of characteristic X-rays increases
• lambda of characteristic X-rays decreases
• lambda of characteristic X-rays does not change

Solution

In an X-ray tube the incoming electrons collide with the electrons of anode and displace them. When the electrons move between orbitals the energy released forms the characterisctic wavelength. So the charactic wavelength depends on the atom or the material of anode and not on the accelerating potential. If we increase the potential the intensity of the X rays is increased.