The absorptivity of Lamp black and platinum black is .

The absorptive power of a black body is _____.

Black lead is

Black lead is

The absorption of hydrogen by platinum is known as :

The absorption of hydrogen by platinum is known as :

The probability of drawing a black card from the black cards is…………

Why does a black board appears black in colour ?

''Lamp black and platinum black are used as perfect black body one for absorption of heat radiation.'' Why ?