Advertisements
Advertisements
प्रश्न
Distinguish between streamlined flow and turbulent flow.
Advertisements
उत्तर
| Streamlined flow | Turbulent Flow | |
| 1. | When a liquid flows such that each particle of the liquid passing a point moves along the same path and has the same velocity as its predecessor then flow is said to be streamlined flow. | When the speed of the moving liquid exceeds the critical speed vc, the motion becomes turbulent. |
| 2. | In a streamline flow, the velocity of a fluid at a given point is always constant. | In a turbulent flow, the velocity of a fluid at any point does not remain constant. |
| 3. | The path taken by the particle in this flow is a curve. | The path taken by the particle in this flow becomes erratic and whirlpool. Like circles. |
| 4. | Streamlines do not change and never intersect. | Streamlines and flow tubes change continuously. |
संबंधित प्रश्न
Fill in the blanks using the word(s) from the list appended with each statement
Viscosity of gases. .. with temperature, whereas viscosity of liquids . . . with temperature (increases / decreases)
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)
(a) What is the largest average velocity of blood flow in an artery of radius 2 × 10–3 m if the flow must remain laminar? (b) What is the corresponding flow rate? (Take viscosity of blood to be 2.084 × 10–3 Pa s).
The force of viscosity is
The viscous force acting between two layers of a liquid is given by \[\frac{F}{A} = - \eta\frac{dv}{dz}\]. This F/A may be called
A raindrop falls near the surface of the earth with almost uniform velocity because
A spherical ball is dropped in a long column of a viscous liquid. The speed of the ball as a function of time may be best represented by the graph
The unit of viscosity is
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
Define the coefficient of viscosity of a liquid.
Define terminal velocity.
Two streamlines cannot cross each other. Why?
Derive Poiseuille’s formula for the volume of a liquid flowing per second through a pipe under streamlined flow.
A block of Ag of mass x kg hanging from a string is immersed in a liquid of relative density 0.72. If the relative density of Ag is 10 and tension in the string is 37.12 N then compute the mass of Ag block.
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)
Choose the CORRECT statement.
In motors, more viscous oil is used in summer than in winter due to ____________.
The velocity of water in river is 8 km/hr of the upper surface. The river is 12 m deep. If the coefficient of viscosity of water is 10-2 poise then the shearing stress between horizontal layers of water is ______.
Analogy
Viscous force: ______:: Buoyant force: ______.
Clouds float in the air due to ______.
The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is `"d"/2`, then the viscous force acting on the ball will be ______
With increase in temperature, the viscosity of ______.
- gases decreases.
- liquids increases.
- gases increases.
- liquids decreases.
A solid ball of density ρ1 and radius r falls vertically through a liquid of density ρ2. Assume that the viscous force acting on the ball is F = krv, where k is a constant and v its velocity. What is the terminal velocity of the ball?
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 ______.
A liquid of density ρ and coefficient of viscosity η flows with velocity v through a tube of diameter D. A quantity `"R" = (rho"vD")/η`, determines whether the flow will be streamlined or turbulent. R has the dimension of ______.
Define velocity gradient.
A force of 0.01 N is required to move a flat glass plate of area of 10 cm2 with a uniform velocity of 1 cm/ s over the surface of a liquid 2 mm thick. If the coefficient of viscosity of the liquid is 20 poise, the velocity gradient in the liquid layer is ______.
The dimensions of coefficient of viscosity are ______.
