Electrons of mass m with de- Broglie wavelength λ fall on the target in an X-ray tube. The cut-off wavelength (λ_o) of the emitted X-ray is:

1.  ${\mathrm{\lambda }}_0=\frac{2{\mathrm{mc\lambda }}^2}{\mathrm{h}}$

2.  ${\mathrm{\lambda }}_0=\frac{2\mathrm{h}}{\mathrm{mc}}$

3.  ${\mathrm{\lambda }}_0=\frac{2{\mathrm{m}}^2{\mathrm{c}}^2{\mathrm{\lambda }}^2}{{\mathrm{h}}^2}$

4.  ${\mathrm{\lambda }}_0=\mathrm{\lambda }$

In a discharge tube ionization of enclosed gas is produced due to collisions between:

1. positive ions and neutral atoms/molecules

2. negative electrons and neutral atoms/molecules

3. photons and neutral atoms/molecules

4. neutral gas atoms/molecules

The minimum wavelength of X-rays produced by 30 kV electrons is:
1. 0.0414 nm
2. 0.0041 nm
3. 0.1410 nm
4. 0.4140 nm

An X-ray tube produces a continuous spectrum of radiation with its short wavelength ending at 0.45 Å. What is the maximum energy of a photon in radiation?
1. \(27.6~ \mathrm{keV} \)
2. \(25.5 ~\mathrm{keV} \)
3. \(23.4 ~\mathrm{keV} \)
4. \(25.1~ \mathrm{keV}\)

Which of the following are true for cathode ray?

(a) It travels along straight lines.
(b) It emits X-ray when strikes a metal.
(c) It is an electromagnetic wave.
(d) It is not deflected by magnetic field

Choose the correct option 

1. (a), (b) 

2. (b), (c)

3. (c), (d) 

4. (a), (d)  

X-ray beam can be deflected

1.  by an electric field

2.  by a magnetic field

3.  by an electric field as well as by a magnetic field

4.  neither by an electric field nor by a magnetic field

Consider a photon of continuous X-ray coming from a Coolidge tube. Its energy comes from

1.  the kinetic energy of the striking electron

2.  the kinetic energy of the free electrons of the target

3.  the kinetic energy of the ions of the target

4.  an atomic transition in the target

If the potential difference applied to the tube is doubled and the separation between the filament and the target is also doubled, the cutoff wavelength

1.  will remain unchanged

2.  will be doubled

3.  will be halved

4.  will become four times the original

If the current in the circuit for heating the filament is increased, the cutoff wavelength

1.  will increase

2.  will decrease

3.  will remain unchanged

4.  will change

The X-ray beam coming from an X-ray tube

1.  is monochromatic

2.  has all wavelengths smaller than a certain maximum wavelength

3.  has all wavelengths greater than a certain minimum wavelength

4.  has all wavelengths lying between a minimum and a maximum wavelength