A tungsten filament in a laboratory lamp initially glows with a peak emission…
PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
A tungsten filament in a laboratory lamp initially glows with a peak emission wavelength of λpeak,1=900nm. When the applied voltage is increased, the peak wavelength shifts to λpeak,2=750nm. Treat the filament as an ideal blackbody.
(a) Determine the ratio T2/T1 of the filament’s absolute temperature after the voltage increase to its initial temperature.
(b) Calculate the percent increase in the filament’s absolute temperature.
(c) Discuss qualitatively how the observed brightness and color of the lamp would be expected to change as a result of the temperature increase. Refer specifically to the regions of the electromagnetic spectrum most affected.