Let nr and nb be respectively the number of photons emitted by a red bulb and a blue bulb of equal power in a given time.

Q: Let n_r and n_b be respectively the number of photons emitted by a red bulb and a blue bulb of equal power in a given time.

(A) n_r = n_b

(B) n_r < n_b

(D) data insufficient

Solution : $\large E = \frac{12400}{\lambda (A^o)}$

Number of Photon $\large N = \frac{P}{E} = \frac{P}{hc/\lambda}$

$\large N = \frac{P \lambda}{h c} $

$\large N \propto \lambda $

Correct option is (C)