A soldering iron glows at 372$\lambda$C.What is the dominant wavelength emitted by the iron?
A)270 µm
B)11 µm
C)7.8 µm
D)4.5 µm
E)650 nm

Question

Quizplus · Accepted Answer

To determine the dominant wavelength of the radiation emitted by a hot object, we need to use Wien's Law. 
Wien's Law states that the wavelength of maximum radiation (λmax) emitted by an object is inversely proportional to its temperature (T). 
λmax = b/T 
where b is a constant called Wien's constant, equal to approximately 2.898 x 10^-3 m·K.

First, we need to convert the temperature of the soldering iron to kelvin: 
T = (372°F - 32) × 5/9 + 273.15 = 645.15 K 
Then, we plug this value into Wien's Law: 
λmax = 2.898 x 10^-3 m·K / 645.15 K = 4.49 x 10^-6 m = 4.49 µm

Therefore, the dominant wavelength emitted by the soldering iron is approximately 4.5 µm. 
The correct answer is D.

A Soldering Iron Glows at 372 λ\lambdaλ CWhat Is the Dominant Wavelength Emitted by the Iron? A)270

A Soldering Iron Glows at 372 $\lambda$ CWhat Is the Dominant Wavelength Emitted by the Iron?
A)270