The potential difference applied to an X-ray tube is 5 kV and the current through it is 3.2 mA. The number of electrons striking the target per second is
Options
(a) 5 x 10¹⁶
(b) 1 x 10¹⁷
(c) 4 x 10¹⁵
(d) 2 x 10¹⁶
Correct Answer:
2 x 10¹⁶
Explanation:
Let n = number of electrons striking per sec.
e = 1.6 × 10⁻¹⁹ = charge on each electron
Charge per second = n × 1.6 × 10⁻¹⁹
Current = n × 1.6 × 10⁻¹⁹
3.2 × 10⁻³ = n × 1.6 × 10⁻¹⁹
n = 3.2 × 10⁻³ / 1.6 × 10⁻¹⁹ = 2 × 10¹⁶