If $f(x) = (x^2 - 1)^7$,then $f^{(14)}(x)$ is equal to

In the circuit shown below,the ammeter reading is zero. Then the value of the resistance $R$ is (in $\Omega$)

The variation of magnetic susceptibility $(\chi )$ with temperature for a diamagnetic substance is best represented by

Which of the following is not a chromophore?

In an elastic collision of two particles,which of the following quantities is conserved?

Two identical bodies have temperatures $277^{\circ} C$ and $67^{\circ} C$. If the surroundings temperature is $27^{\circ} C$, the ratio of loss of heats of the two bodies during the same interval of time is (approximately) (in $19 : 1$)