The length of metallic wire is $l_1$ when tension in it is $T_1$. It is $l_2$ when the tension is $T_2$. The original length of the wire will be :

A cylindrical vessel containing a liquid is rotated about its axis so that the liquid rises at its sides as shown in the figure. The radius of vessel is $5 \mathrm{cm}$ and the angular speed of rotation is $\mathrm{\omega } \mathrm{rad} {\mathrm{s}}^{-1}$. The difference in the height, $\mathrm{h} \left(\mathrm{in} \mathrm{cm}\right)$ of liquid at the Centre of vessel and at the sides of the vessel will be :

When a long glass capillary tube of radius $0.015 \mathrm{cm}$ is dipped in a liquid, the liquid rises to a height of $15 \mathrm{cm}$ within it. If the contact angle between the liquid and glass is close to $0°$, the surface tension of the liquid, is $n$ Millinewton ${\mathrm{m}}^{-1}$. Write the value of $100n$.

$\left[{\rho }_{\text{(liquid) }}=900 \mathrm{kg} {\mathrm{m}}^{-3}, \mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}\right]$