Fluid Mechanics - Physics PYQ | AP EAPCET

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

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 cm. Find the radius of the capillary tube used, if surface tension of water is 7.5 \(\times\) 10\(^{-2}\) Nm\(^{-1}\). Angle of contact between water and glass is 0\(\Upsilon\) and acceleration due to gravity is 10 ms\(^{-2}\).

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

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

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.

A glass flask weighting 390 g, having internal volume 500 cc just floats when half of it is filled with water. Specific gravity of the glass is

Water does not wet an oily glass because

In a hydraulic lift, compressed air exerts a force \(F\) on a small piston of radius 3 cm . Due to this pressure the second piston of radius 5 cm lifts a load of 1875 kg . The value of \(F\) is (Acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\))

In a \(U\)-shaped tube the radius of one limb is 2 mm and that of other limb is 4 mm . A liquid of surface tension \(0.03 \mathrm{~Nm}^{-1}\), density \(1500 \mathrm{~kg} \mathrm{~m}^{-3}\) and angle of contact zero is taken in the tube. The difference in the heights of the levels of the liquid in the two limbs is (Acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\))

A steady flow of a liquid of density \(\rho\) is shown in figure. At point 1, the area of cross-section is \(2 A\) and the speed of flow of liquid is \(\sqrt{2} \mathrm{~ms}^{-1}\). At point 2 , the area of cross-section is \(A\). Between the points 1 and 2, the pressure difference is \(100 \mathrm{~Nm}^{-2}\) and the height difference is 10 cm . The value of \(\rho\) is (Acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\))

Statement (A) When the temperature increases the viscosity of gases increases and the viscosity of liquids decreases.

Statement (B) Water does not wet an oily glass because cohesive force of oil is less than that of water.

Statement (C) A liquid will wet a surface of a solid, if the angle of contact is greater than \(90^{\circ}\).

A hydraulic lift is shown in the figure. The movable pistons \(A, B\) and \(C\) are of radius \(10 \mathrm{~cm}, 100 \mathrm{~m}\) and 5 cm respectively. If a body of mass 2 kg is placed on piston \(A\), the maximum masses that can be lifted by piston \(B\) and \(C\) are respectively.