A bulb is rated at 150 watt, converting 8 % energy into light. If energy of one photon is 4.42 10⁻¹⁹ J, how many photons are emitted by the bulb per second ?

Step-by-step solution

Power of the bulb, P = 150 W Energy converted into light per second, E = 8 % of 150 J E = 8 100 150 = 12 J Energy of one photon, E_p = 4.42 10⁻¹⁹ J Number of photons emitted per second, n = E E_p n = 12 4.42 10⁻¹⁹ n = 2.71 10¹⁹ Answer: 2.71 10¹⁹