Question

Assertion : Blue star is at high temperature than red star.
Reason : Wein's displacement law states that $T \mu; (1/\lambda_m )$.

• A. If both the assertion and reason are true and reason is a correct explanation of the assertion
• B. If both assertion and reason are true but assertion is not a correct explanation of the assertion
• C. If the assertion is true but the reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (A)

From Wien’s displacement law, temperature $(T ) \propto 1/\lambda _ m$ (where $\lambda_m$ is the maximum wavelength). Thus temperature of a body is inversely proportional to the wavelength. Since blue star has smaller wavelength and red star has maximum wavelength, therefore blue star is at higher temperature then red star.