A 100 watt bulb emits light of wavelength ' x ' Å . What is the value of x , if the number of photons emitted is 2.0 10²⁰ ~s ⁻¹ ? ( h =6.63 10⁻³⁴ Js , 1 . watt .=1 Js ⁻¹ )

Step-by-step solution

Power =100 watt =100 Js ⁻¹ Number of photons emitted =2.0 10²⁰ ~s ⁻¹ Wavelength = x Energy of 1 photon = h c As, Total Energy ( Power )= Number of photons emitted Energy of 1 photon aligned & 100 ~J ~s ⁻¹=2.0 10²⁰ ~s ⁻¹ hc & 100 ~J ~s ⁻¹= 2.0 10²⁰ ~s ⁻¹ 6.63 10⁻³⁴ Js 3 10^8 ~ms ⁻¹ & = 6 6.63 10⁻⁶ ~m 100 =39.78 10⁻⁸ ~m =3978 Å aligned