The law used in the measurement of the temperature of stars is .........

The black discs $x, y$ and $z$ have radii $1 \ m, 2 \ m$ and $3 \ m$ respectively. The wavelengths corresponding to maximum intensity are $200 \ nm, 300 \ nm$ and $400 \ nm$ respectively. The relation between emissive power $E_{x}, E_{y}$ and $E_{z}$ is

$A$ black body emits radiations of maximum intensity at a wavelength of $5000 \mathring A$,when the temperature of the body is $1227^{\circ}C$. If the temperature of the body is increased by $1000^{\circ}C$,the maximum intensity of emitted radiation would be observed at..... $\mathring A$.

Four pieces of iron heated in a furnace to different temperatures show different colours listed below. Which one has the highest temperature?

The graph of relative intensity versus wavelength for three perfectly black bodies at temperatures $T_1, T_2,$ and $T_3$ is shown below. The relationship between their temperatures is:

We consider the radiation emitted by the human body. Which of the following statements is true?