Note:

If your answer is options 2,4 Then you have to fill the OMR sheet as ‘24’
If your answer is options 1,3,4 Then you have to fill the OMR sheet as ‘134’
 

 

In an X-ray tube, electrons emitted from a filament (cathode) carrying current I hit a target (anode) at a distance d from the cathode. The target is kept at a potential V higher than the cathode resulting in emission of continuous and characteristic X-rays. If the filament current I is decreased to $\frac{I}{2},$ the potential difference V is increased to 2V, and the separation distance d is reduced to $\frac{d}{2},$ then
1) the cut-off wavelength will reduce to half, and the wavelengths of the characteristic X-rays will remain the same
2) the cut-off wavelength as well as the wavelengths of the characteristic X-rays will remain the same
3) the cut-off wavelength will reduce to half, and the intensities of all the X-rays will decrease
4) the cut-off wavelength will become two times lager, and the intensity of all the X-rays will decrease