First slide

Classical atomic models

Question

A 600 W mercury lamp emits monochromatic radiation of wavelength 331.3 nm. How many photons are emitted from the lamp per second?
$(h = 6.626 \times 10^{- 34} Js; velocity of light = 3 \times 10^{8} {ms}^{-})$

Moderate

A

$1 \times 10^{19}$
B

$1 \times 10^{20}$
C

$1 \times 10^{21}$
D

$1 \times 10^{23}$

Solution

$600 W = 600 J s^{- 1}$
$∴$ Energy emitted per second = 600 J
Energy of one photon $= \frac{h c}{λ}$
$= \frac{6.626 \times 10^{- 34} J s \times 10^{8} m s^{- 1}}{313.3 \times 10^{- 9} m}$
$= 6.394 \times 10^{- 19}$
Photon emiited per second $= \frac{600}{6.344 \times 10^{- 19}} \approx 1 \times 10^{21}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App