A transmitter of power 10 kW emits radio waves of wavelength 500 m . The number of photons emitted per…
A transmitter of power 10 kW emits radio waves of wavelength 500 m . The number of photons emitted per second by the transmitter is of the order of
$10^{37}$
$10^{31}$
$10^{25}$
$10^{43}$
Solution
Power, $P=\frac{n h c}{\lambda t}$
$\therefore \quad$ Number of photons emitted per second,
$\begin{aligned}
& \frac{\mathrm{n}}{\mathrm{t}}=\frac{\pi \lambda}{\mathrm{hc}}=\frac{\left(10 \times 10^3\right) \times\left(500 \times 10^{10} \mathrm{~A}^{\circ}\right)}{\left(12375 \times 1.6 \times 10^{-19} \mathrm{~J}-\mathrm{A}^{\circ}\right)} \\
& =2.52 \times 10^{31}
\end{aligned}$
$\therefore \quad$ It is of the order of $10^{31}$.