If \(\lambda_m\) is the wavelength, corresponding to which the radiant intensity of a block is at its maximum and its absolute temperature is \(T,\) then which of the following graphs correctly represents the variation of \(T?\)

1.		2.
3.		4.

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using

1. Stefan's law
2. Wien's displacement law
3. Kirchoff's law
4. Newton's law of cooling

According to Wein's law:
1. ${\mathrm{\lambda }}_{\mathrm{m}}\mathrm{T}$= constant                 

2. $\frac{{\mathrm{\lambda }}_{\mathrm{m}}}{\mathrm{T}}$= constant

3. $\frac{T}{{\mathrm{\lambda }}_{\mathrm{m}}}$= constant                 

4. $\mathrm{T}+{\mathrm{\lambda }}_{\mathrm{m}}$= constant

On investigation of light from three different stars A, B and C, it was found that in the spectrum of A the intensity of red colour is maximum, in B the intensity of blue colour is maximum and in C the intensity of yellow colour is maximum. From these observations it can be concluded that

(1) The temperature of A is maximum, B is minimum and C is intermediate

(2) The temperature of A is maximum, C is minimum and B is intermediate

(3) The temperature of B is maximum, A is minimum and C is intermediate

(4) The temperature of C is maximum, B is minimum and A is intermediate

The wavelength of radiation emitted by a body depends upon 

(1) The nature of its surface

(2) The area of its surface

(3) The temperature of its surface

(4) All the above factors