Question

The temperature of a black body is gradually increased. The colour of the body will change from

• A. White - green - red
• B. Red-yellow-blue
• C. Red-violet-yellow
• D. Yellow-green-red

Answer 1

The correct option is B Red-yellow-blue

According to Wien's displacement law,

${\lambda }_{m}T=constant$

$\therefore$ As the temperature is increased, $\lambda$ is decreased in the visible spectrum,

VIBGYOR, ${\lambda }_R>{\lambda }_Y>{\lambda }_B$

$\therefore$ The colour will change from red to yellow to blue.

option (B) is correct .