Thermal Properties Of Matter Ques 25

25. A black body at $1227^{\circ} C$ emits radiations with maximum intensity at a wavelength of $5000$ $ \AA$. If the temperature of the body is increased by $1000^{\circ} C$, the maximum intensity will be observed at

[2006]

(a) $5000 $ $\AA$

(b) $6000 $ $\AA$

(c) $3000 $ $\AA$

(d) $4000 $ $\AA$

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Answer:

Correct Answer: 25.(c)

Solution:

  1. (c) Applying Wein’s displacement law,

$ \lambda_m T=\text{ constant } $

$5000 \AA \times(1227+273)=(2227+273) \times \lambda_m$

$\lambda_m=\frac{5000 \times 1500}{1000}=3000 $ $\AA$