Question

The voltage applied to an X-ray tube is 18 kV. The maximum mass of photon emitted by theX-ray tube will be-

• A. 2 × 10^–13 kg
• B. 3.2 × 10^–36 kg
• C. 3.2 × 10^–32 kg
• D. 9.1 × 10^–31 kg

Answer 1

Answer: (C)

3.2 × 10^–32 kg

Answer 2

Energy of photon is given by mc² now the maximum energy of photon is equal to the maximum energy of electron = eV

Hence,mc² =eV Žm= $\frac { \mathrm { eV } } { \mathrm { c } ^ { 2 } }$ =$\frac { 1.6 \times 10 ^ { - 19 } \times 18 \times 10 ^ { 3 } } { \left( 3 \times 10 ^ { 8 } \right) ^ { 2 } }$

= 3.2 × 10^–32 kg