HC Verma Class 11 Physics Chapter-13 Solutions

Is it always true that the molecules of a dense liquid are heavier than the molecules of a lighter liquid?

If someone presses a pointed needle against your skin, you are hurt. But if someone presses a rod against your skin with the same force, you easily tolerate. Explain.

In the derivation of P₁ - P₂ = ρgz, it was assumed that the liquid is incompressible. Why will this equation not be strictly valid for a compressible liquid?

Suppose the density of air at Madras is ρ₀ and atmospheric pressure is P₀. If we go up, the density and the pressure both decrease. Suppose we wish to calculate the pressure at a height 10 kin above Madras. If we use the equation P₀ - P = ρ₀gz, will we get a pressure more than the actual or less than the actual? Neglect the variation in g. Does your answer change if you also consider the variation in g?

The free surface of a liquid resting in an inertial frame is horizontal. Does the normal to the free surface pass through the center of the earth? Think separately if the liquid is (a) at the equator (b) at a pole (c) somewhere else.

A barometer tube reads 76 cm of mercury. if the tube is gradually inclined keeping the open end immersed in the mercury reservoir, will the length of mercury column be 76 cm, more than 76 cm or less than 76 cm?

A one-meter long glass tube is open at both ends. One end of the tube is dipped into a mercury cup, the tube is kept vertical and the air is pumped out of the tube by connecting the upper end to a suction pump. Can mercury be pulled up into the pump by this process?

A satellite revolves round the earth. Air pressure inside the satellite is maintained at 76 cm of mercury. What will be the height of mercury column in a barometer tube 1 m long placed in the satellite?

Consider the barometer shown in figure (13-Q1). If a small hole is made at a point P in the barometer tube, will the mercury come out from this hole?

Is Archimedes’ principle valid in an elevator accelerating up? In a car accelerating on a level road?