Embibe Experts Solutions for Chapter: Mechanical Properties of Matter, Exercise 1: AP EAPCET - 20 Aug 2021 Forenoon

An ideal liquid flows through a horizontal tube of variable diameter. The pressure is lowest where the _____.

Assertion (A): The upper surface of the wing of an aeroplane is made convex and the lower surface is made concave.
Reason (R): The air currents at the top have smaller velocity and thus less pressure at the bottom than at the top.

What causes the free surface of a liquid to have minimum area?

The dimensions of stress is

The lower end of a capillary tube is dipped into water and it is observed that the water in capillary tube rises by $7.5 \mathrm{cm}$. Find the radius of the capillary tube used, if surface tension of water is $7.5\times {10}^{-2} \mathrm{N} {\mathrm{m}}^{-1}$? Angle of contact between water and glass is $0°$ and acceleration due to gravity is $10 \mathrm{m} {\mathrm{s}}^{-2}$.

Identify the incorrect statement regarding Reynold's number $\left(R_e\right):$

The Young's modulus of a rubber string of length $12 \mathrm{cm}$ and density $1.5 \mathrm{kg} {\mathrm{m}}^{-3}$ is $5\times {10}^8 \mathrm{N} {\mathrm{m}}^{-2}$. When this string is suspended vertically, the increase in its length due to its own weight is (take $\mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}$)

Young's modulus of a wire is $2\times {10}^{11} \mathrm{N} {\mathrm{m}}^{-2}$. If an external stretching force of $2\times {10}^{11} \mathrm{N}$ is applied to a wire of length $L$, the final length of the wire is (cross-section$=$unity)