Question

Now slowly begin to raise the temperature. At approximately what temperature would a heated material (metal, wood, etc.) begin to give off visible light at a deep red color?Note: This will be the temperature where your spectrum first begins to come off of the wavelength axis in the visible region, and so is giving off a small amount of red light.
A. 500 K (440 Fahrenheit)
B. 1050 K (1430 Fahrenheit)
C. 1800 K (2780 Fahrenheit)
D. 2500 K (4040 Fahrenheit)

Answer 1

Answer:

Explanation:

We shall apply Wien's displacement law which is as follows .

λ T = b where λ is wavelength of light that is coming out of hot body to maximum extent .

Putting the value of temperature given and b

λ x 500 = 2898 μmK

λ = 5.796 μm = 5796 nm

For temp 1050 K

λ = 2760 nm

For temp 1800 K

λ = 1610  nm

For temp 2500 K

λ = 1159.2  nm

The visible range starts from 740 nm .

Hence we can expect that some amount of visible light may emerge at the temperature of 2500K because the wavelength that we have calculated above gives the value of peak wavelength of a spectrum of light coming out of hot body .