Question

Number of photons of wavelength 600 nm emitted per second by an electric bulb of power 60 W is -

• A. 60
• B. 600
• C. 2 × 10²⁰
• D. None of these

Answer 1

Answer: (C)

2 × 10²⁰

Answer 2

P =

n = $\frac { 60 \times 600 \times 10 ^ { - 9 } } { 6.6 \times 10 ^ { - 34 } \times 3 \times 10 ^ { 8 } }$

n = 18.18 × 10¹⁹

or n = 1.8 × 10²⁰