$A$ rope is used to lower a block of mass $M$ vertically by a distance $x$ with a constant downward acceleration of $\frac{g}{2}$. The work done by the rope on the block is:

Which of the following magnetic properties is exhibited by the compounds of alkaline earth metals?

$A$ deflection magnetometer is adjusted and a magnet of magnetic moment $M$ is placed on it in the usual manner and the observed deflection is $\theta$. The period of oscillation of the needle before settling of the deflection is $T$. When the magnet is removed,the period of oscillation of the needle is $T_0$ before settling to $0^{\circ}-0^{\circ}$. If the earth's horizontal magnetic field is $B_H$,the relation between $T$ and $T_0$ is

Which of the following is absent in polluted water?

What is the product obtained from the dehydration of glycerol?

What is the protective protein coat of a virus known as?