F.M 1.4 Viscosity-1

Water flows between two plates of which the upper one is stationary and the lower one is moving with a velocity V. What will be the velocity of the fluid in contact with the upper plate?

• V

• $\frac{N}{2}$
  

• 2V

• 0

The viscous force the relative motion between the adjacent layers of a fluid in motion.

Which one of the flowing fits best in the sentence?

• opposes

• never affects

• facilitates

• may effect under certain conditions

The viscosity of a fluid in motion is 1 Poise. What will be it’s viscosity (in Poise) when the fluid is at rest?

• 0

• 0.5

• 1

• 2

Answer explanation

2

Which of the following correctly states how the viscosities of a liquid and a gas will change with temperature?

• Viscosity increases with the increase in temperature of a liquid and decreases with the increase in temperature of a gas

• Viscosity increases with the increase in temperature of a liquid and increases with the increase in temperature of a gas

• Viscosity decreases with the increase in temperature of a liquid and decreases with the increase in temperature of a gas

• Viscosity decreases with the increase in temperature of a liquid and increases with the increase in temperature of a gas

Which one of the following is not a unit of dynamic viscosity?

• $Pa-s$
  

• $N-\frac{s}{m^2}$
  

• Poise

• Stokes

Which of the following is a unit of dynamic viscosity?

• $\left[M_1L_1T_{-1}\right]$

• $\left[M_1L_{-1}T_{-1}\right]$

• $\left[M_1L_{-2}T_{-2}\right]$

• $\left[M_1L_{-2}T_{-2}\right]$

Which one of the following is the CGS unit of dynamic viscosity?

• Stokes

• $Pa-s$
  

• $\frac{m^2}{s}$

• Poise

The dynamic viscosity of a fluid is 1 Poise. What should one multiply to it to get the answer in $N-\frac{s}{m^2}$  ?

• 0.1

• 1

• 10

• 1000

Which of the following is a unit of kinematic viscosity?

• Stokes

• $Pa-s$

• $m^2=s$

• Poise

Which of the following is the dimension of kinematic viscosity?

• $\left[L_1T_{-1}\right]$

• $\left[L_1T_{-2}\right]$

• $\left[L_2T_{-1}\right]$

• $\left[L_2T_{-2}\right]$