Question

About black body radiation, which one of the following is \(\textbf{WRONG}\) statement?

• A. For all wavelengths, intensity is same.
• B. All wavelengths are emitted by a black body.
• C. For longer wavelengths, intensity is less.
• D. For shorter wavelengths, intensity is more.

Hint:

Black body radiation has a peak intensity at a particular wavelength, not a uniform distribution.

Answer 1

The Correct Option is A

Step 1: Nature of black body radiation spectrum.
A black body emits radiation over a continuous range of wavelengths, but the intensity is not the same for all wavelengths.

Step 2: Distribution of intensity.
The intensity first increases with wavelength, reaches a maximum at a particular wavelength, and then decreases for longer wavelengths.

Step 3: Analyze the options.
Option (A) is incorrect because intensity varies with wavelength.
Options (B), (C), and (D) correctly describe characteristics of black body radiation.

Step 4: Conclusion.
The wrong statement is that intensity is the same for all wavelengths.