JEE Advanced 2020Paper 2
- Exam
- JEE Advanced
- Year
- 2020
- Paper
- Paper 2
- Subject
- Physics
- Chapter
- Electromagnetic Waves
JEE Advanced 2020 · Paper 2 · Physics · Electromagnetic Waves
In an X -ray tube, electrons emitted from a filament (cathode)...
In an -ray tube, electrons emitted from a filament (cathode) carrying current hit a target (anode) at a distance from the cathode. The target is kept at a potential higher than the cathode resulting in emission of continuous and characteristic X-rays. If the filament current is decreased to the potential difference is increased to and the separation distance is reduced to then
Options
- Athe cut-off wavelength will reduce to half, and the wavelengths of the characteristic X-rays will remain the same
- Bthe cut-off wavelength as well as the wavelengths of the characteristic X-rays will remain the same
- Cthe cut-off wavelength will reduce to half, and the intensities of all the X-rays will decrease
- Dthe cut-off wavelength will become two times larger, and the intensity of all the X-rays will decrease
Correct answer
A. the cut-off wavelength will reduce to half, and the wavelengths of the characteristic X-rays will remain the same
Step-by-step solution
Cut off wavelength
So, cut-off wavelength becomes half.
Characteristic x-ray depends on target atomic number, so it remains same.
On decreasing filament current number of electron decrease, so intensity of -ray decreases.