What is $DDT$?

Cornea transplant in humans is almost never rejected. This is because

According to the law of equipartition of energy,the molar specific heat of a diatomic gas at constant volume,where the molecule has one additional vibrational mode,is:

If $N$ is the number of turns in a coil,the value of self-inductance varies as

Which gas is released when $Na_2CO_3$ is heated?

Two thin lenses of focal lengths $f_1$ and $f_2$ are in contact and coaxial. The power of the combination is