Concepts Of Physics MCQ Edition [Volume 2]PhysicsX-rays
When the current in the circuit used to heat the filament is increased, the cutoff wavelength
Options
- Awill change
- Bwill increase
- Cwill decrease
- Dwill remain unchanged
Correct answer
D. will remain unchanged
Step-by-step solution
The cutoff wavelength (or minimum wavelength) of the continuous X-ray spectrum is given by: _ min = hc eV where V is the accelerating potential difference between the cathode and the anode. The current in the filament circuit only controls the temperature of the filament. An increase in filament current increases the number of electrons emitted per second due to thermionic emission, which increases the intensity of the X-rays produced. However, it does not change the maximum kinetic energy of the electrons striking