The energy of an X -ray photon is 2 keV, then its Frequency will be:

Question

The energy of an X -ray photon is 2 keV, then its Frequency will be: (A)  3.2× 10-6 per sec (B)  5× 1017 per sec (C)  2× 1017 per sec (D)  2× 1018 per sec

Tardigrade Admin · Accepted Answer

For the most favourable collision in which the electron loses, the whole of its energy in a single collision with the target atom, an X-ray photon of maximum energy

h v

is emitted

E = h v

where

h

is Planck's constant and

v

is frequency.
Given,

E = 2 k e V

= 2 \times 1 0^{3} \times 1.6 \times 1 0^{- 19} J

\Rightarrow v = \frac{E}{h} = \frac{2 \times 1 0 ^{3} \times 1.6 \times 1 0 ^{- 19}}{6.6 \times 1 0 ^{- 34}}

= 9.84 \times 1 0^{17}

\approx 5 \times 1 0^{17} / s

Note : Since, energy

\propto

frequency, higher the energy higher the frequency.

Q. The energy of an $X$ -ray photon is $2 k e V$ , then its Frequency will be:

$3.2 \times 10^{- 6}$ per sec

$5 \times 10^{17}$ per sec

$2 \times 10^{17}$ per sec

$2 \times 10^{18}$ per sec

Q. The energy of an X -ray photon is 2keV, then its Frequency will be:

3.2×10−6 per sec

5×1017 per sec

2×1017 per sec

2×1018 per sec

Q. The energy of an $X$ -ray photon is $2 k e V$ , then its Frequency will be:

$3.2 \times 10^{- 6}$ per sec

$5 \times 10^{17}$ per sec

$2 \times 10^{17}$ per sec

$2 \times 10^{18}$ per sec