Question

Calculate the wavelength of maximum emission for a tungsten lamp operating at 2870 K. By what factor will its output intensity increase if we raise its temperature to 3000 K?

Answer 1

× T = 2.898×10^-3 m.K

= 2.898×10^-3m.K /2870K = 1.01×10^-6 m

Wavelength of maximum emission = 1.01×10^-6 m. (answer)

Intensity is directly proportional to 4th power of temperature. (T^{​​​​​​4} )

I_{​​​​​​2} = (T2/T1)⁴ × I_{​​​​​​1}

_{= (3000/2870)}⁴ × I_{​​​​​​1}

= 1.194 I_{​​​​​​1} ~ 1.2× I_{​​​​​​1}

The output intensity would increases by a factor of 1.2 times.(answer)