Exercise - 3

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Embibe Experts Physics Solutions for Exercise - 3

Simple step-by-step solutions to Exercise - 3 questions of Viscosity and Surface Tension from Alpha Question Bank for Engineering: Physics. Also get 3D topic explainers, cheat sheets, and unlimited doubts solving on EMBIBE.

Questions from Exercise - 3 with Hints & Solutions

MEDIUM
JEE Main/Advance
IMPORTANT

A small sphere falls from rest in a viscous liquid. Due to friction, heat is produced. Find the relation between the rate of production of heat and the radius of the sphere at terminal velocity.

HARD
JEE Main/Advance
IMPORTANT

Two spheres P and Q of equal radii have densities ρ1 and ρ2, respectively. The spheres are connected by a massless string and placed in liquids L1 and L2 of densities σ1 and σ2 viscosities η1 and η2, respectively. They float in equilibrium with the sphere P in L1 and sphere Q in L2 and the string is being taut (see figure). If sphere P alone in L2 has terminal velocity VP and Q alone in L1 has terminal velocity VQ, then

Question Image 

MEDIUM
JEE Main/Advance
IMPORTANT

Consider a thin square plate floating on a viscous liquid in a large tank. The height h of the liquid in the tank is much less than the width of the tank. The floating plate is pulled horizontally with a constant velocity u0. Which of the following statements is (are) true?

MEDIUM
JEE Main/Advance
IMPORTANT

Spherical balls of radius r Are falling in a viscous fluid of viscosity η with a velocity v. The retarding viscous force acting on the spherical ball is:

HARD
JEE Main/Advance
IMPORTANT

A spherical solid ball of volume V is made of a material of density ρ1. It is falling through a liquid of density ρ2ρ2<ρ1. [Assume that the liquid applies a viscous force on the ball that is proportional to the square of its speed v, i.e. Fviscous=-k^v2(k>0)]. The terminal speed of the ball is

MEDIUM
JEE Main/Advance
IMPORTANT

A tiny spherical oil drop carrying a net charge q is balanced in still air with a vertical uniform electric field of strength 81π7×105 V m-1. When the field is switched off, the drop is observed to fall with terminal velocity 2 × 103 m s1. Given g= 9.8 m s-2, viscosity of the air = 1.8 × 105 N s m2  and the density of oil = 900 kg m3,  the magnitude of q is: