1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# Calculate the number of photons emitted per second by a 10 W sodium vapour lamp. Assume that 50% of the consumed energy is converted into light. Wavelength of sodium light = 600 nm. Take h=6.6×10−34 Js and c=3×108ms−1

A
15.15×1018
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
25.25×1018
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2.52×1019
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
1.51×1018
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is A 15.15×1018We know, power is the energy transferred or converted per unit time. Since power is given as 10 W, so energy consumed in 1 sec is = 10 J But, given that 50 % of the consumed energy is converted into light. So energy used = 5 J Again, energy (E)=nhcλ=n×6.6×10−34×3×108600×10−9 (Where n = number of photons) So 5=n×6.6×10−34×3×108600×10−9 ⇒n=5×600×10−96.6×10−34×3×108 ⇒n=15.15×1018

Suggest Corrections
1
Join BYJU'S Learning Program
Related Videos
Photoelectric Effect
CHEMISTRY
Watch in App
Explore more
Join BYJU'S Learning Program