question_answer

                                  Assertion             :       For higher temperature, the peak emission wavelength of a black body shifts to lower wavelengths.     Reason                 :       Peak emission wavelength of a blackbody is proportional to the fourth power of temperature.             [AIIMS 2005]

A)             If both assertion and reason are true and the reason is the correct explanation of the assertion.

B)             If both assertion and reason are true but reason is not the correct explanation of the assertion.

C)             If assertion is true but reason is false.

D)             If the assertion and reason both are false.

E)             If assertion is false but reason is true.

Correct Answer: C

Solution :

                   According to Weins law \[{{\lambda }_{m}}T\]= constant i.e., peak emission wavelength \[{{\lambda }_{m}}\propto \frac{1}{T}.\] Also as T increases \[{{\lambda }_{m}}\] decreases. Hence assertion is true but reason is false.