Question

A 1-kW radio transmitter operates at a frequency of 880 Hz. How many photons per second does it emit?

• A. $1.71\times {10}^{21}$
• B. $1.71\times {10}^{30}$
• C. $6.02\times {10}^{23}$
• D. $2.85\times {10}^{26}$

Answer 1

The correct option is B $1.71\times {10}^{30}$

$E=hv$

where

$h=$plank's constant =6.62 $\times$ 10${}^{-34}$

$v=$frequency=880Hz

$E=(6.62\times {10}^{-34}Js)\left(880s^{-1}\right)$

$=5.831\times {10}^{-31}J$.

No. of photons emitted $=\frac{1}{5.831}\times {10}^{+31}=1.71\times {10}^{30}$ per second.

Hence, the correct option is $B$