A mass ' M ' is suspended by a rope from a rigid support at point ' P ' as shown in figure. Another rope is tied at end ' Q ' and pulled horizontally with a force ' $F$ '. If the rope makes an angle ' $\theta$ ' with vertical then the tension in the string ' PQ ' is

A mass ' $M$ ' attached to a horizontal spring executes S.H.M. of amplitude $A_1$. When the mass M passes through its mean position, then a smaller mass ' $m$ ' is placed over it and both of them move together with amplitude $\mathrm{A}_2$. The ratio $\left(\frac{A_1}{A_2}\right)$ is

The function of a dielectric in a capacitor is

When one end of the capillary is dipped in water, the height of water column is ' $h$ '. The upward force of 108 dyne due to surface tension is balanced by the force due to the weight of water column. The inner circumference of the capillary is (surface tension of water $=7.2 \times 10^{-2} \mathrm{~N} / \mathrm{m}$ )