Advertisements
Advertisements
प्रश्न
A small sphere of radius 2 cm falls from rest in a viscous liquid. Heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity is proportional to
विकल्प
22
23
24
25
Advertisements
उत्तर
25
APPEARS IN
संबंधित प्रश्न
Fill in the blanks using the word(s) from the list appended with each statement
For solids with elastic modulus of rigidity, the shearing force is proportional to . . . , while for fluids it is proportional to . .. (shear strain / rate of shear strain)
In Millikan’s oil drop experiment, what is the terminal speed of an uncharged drop of radius 2.0 × 10–5 m and density 1.2 × 103 kg m–3? Take the viscosity of air at the temperature of the experiment to be 1.8 × 10–5 Pa s. How much is the viscous force on the drop at that speed? Neglect buoyancy of the drop due to air.
Water flows at a speed of 6 cm s−1 through a tube of radius 1 cm. Coefficient of viscosity of water at room temperature is 0.01 poise. Calculate the Reynolds number. Is it a steady flow?
Which has greater viscosity, oil or honey? Why?
With an increase in temperature, the viscosity of liquid and gas, respectively will __________.
A small metal sphere of mass M and density d1, when dropped in a jar filled with liquid moves with terminal velocity after sometime. The viscous force acting on the sphere is (d2 = density of liquid and g = gravitational acceleration)
Analogy
Viscous force: ______:: Buoyant force: ______.
A spherical solid ball of volume V is made of a material of density ρ1. It is falling through a liquid of density ρ2 (ρ2 < ρ1). Assume that the liquid applies a viscous force on the ball that is proportional to the square of its speed v, i.e., `"F"_"viscous"`= -kv2 (k > 0). The terminal speed of the ball is ______.
The coefficient of apparent expansion of mercury in a glass vessel is 153 × 10-6/°C and in a steel vessel is 144 × 10-6/°C. If α for steel is 12 × 10-6/°C, then that of glass is ______.
Define velocity gradient.
