The correct option is C 4.15×1019
Given,
Power of the bulb =100 watt=100 J s−1
So, the energy released by the bulb in the form of light per second =100×15100 J=15 J
Again, the wavelength of emitted light, λ=5500 ∘A
We know,
E=nhv=n×hcλ=Energy emitted by bulb in the form of light
Thus,
n×hc5500×10−10=15 J
⇒n×6.62×10−34×3×1085500×10−10=15 J
⇒n=4.15×1019