A black body has a wavelength ${\lambda }_m$ corresponding to maximum energy at 2000 K. Its wavelength corresponding to maximum energy at 3000 K will be:

1. $\frac{3}{2}{\lambda }_m$

2. $\frac{2}{3}{\lambda }_m$

3. $\frac{16}{81}{\lambda }_m$

4. $\frac{81}{16}{\lambda }_m$

Wien's displacement law expresses the relation between:
 

If λ_m denotes the wavelength at which the radioactive emission from a black body at a temperature T K is maximum, then:

1. λ_m is independent of T

2. λ_m ∝ T

3. λ_m ∝ T^–1

4. λ_m ∝ T^{– 4}