Multiple Choice
A light bulb emits light uniformly in all directions. What is the electric field amplitude away from the light bulb?
32. Electromagnetic Waves
Intensity of EM Waves
Struggling with Physics?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Suppose a certain star has a temperature of At what wavelength will this star emit the most energy?
A
B
C
D
E
F
Verified step by step guidance1
Understand that the problem is asking for the wavelength at which the star emits the most energy. This is related to the concept of blackbody radiation, where the peak wavelength is determined by the temperature of the star.
Use Wien's Displacement Law, which states that the wavelength of maximum emission, \( \lambda_{max} \), is inversely proportional to the temperature \( T \) of the blackbody. The formula is \( \lambda_{max} = \frac{b}{T} \), where \( b \) is Wien's constant, approximately \( 2.897 \times 10^{-3} \) m·K.
Substitute the given temperature of the star, \( T = 7000 \) K, into Wien's Displacement Law to find \( \lambda_{max} \). The calculation will be \( \lambda_{max} = \frac{2.897 \times 10^{-3}}{7000} \) meters.
Convert the result from meters to nanometers, since the options provided are in nanometers. Remember that 1 meter equals 1,000,000,000 nanometers.
Compare the calculated wavelength in nanometers to the given options (110 nm, 200 nm, 290 nm, 490 nm, 580 nm) to identify the closest match to the calculated \( \lambda_{max} \).
8:26mWatch next
Master Intensity of EM Waves with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Intensity of EM Waves practice set
Problem sets built by lead tutorsExpert video explanations