11th class (Fsc) Physics unit 6 MCQs
chapter 6 MCQs 11th Class Physics
Fluid Dynamics:
1. The law of conservation of mass gives:
a. Torricelli’s theorem
b. Bernoulli’s
c. Equation of continuity
d. Venture relation
2. Stoke’s law holds for bodies having:
a. Rectangular shape
b. Spherical shape
c. All shapes
d. Oblong shape
3. The dimensions of viscosity are:
a. [M-1L-1T]
b. [M2L-2T-2]
c. [ML-1T-1]
d. [M-1LT-1]
4. Which material has maximum viscosity?
a. Methanol
b. Glycerin
c. Water
d. Plasma
5. If the radius of droplet becomes half, then its terminal velocity will become:
a. One fourth
b. Double
c. Remains same
d. Half
6. When a body acquires terminal velocity then its acceleration “a” becomes:
a. a>0
b. a=0
c. a<0
d. a=g
7. A fog droplet falls vertically through air with an acceleration :
a. zero
b. Equal to ‘g’
c. Greater than “g”
d. Less than “g”
8. The terminal velocity of a droplet falling down under gravity is directly proportional to the square of:
a. Its viscosity
b. Its density
c. Its elasticity
d. Its radius
9. Two fog droplets are in freely falling condition. The ratio of their radii is 2:3, the ratio of their terminal velocities will be:
a. 4:9
b. 2:3
c. 9:4
d. 4:6
10. The SI units of flow rate are:
a. m3s-1
b. m2s-1
c. m2s-2
d. m3s-2
11. The unit of coefficient of viscosity n SI system is:
a. Kg-1m-1s
b. Kg-1ms-1
c. Kgms-1
d. Kgm-1s-1
12. The word FLUID means:
a. To flow
b. To rise
c. To oppose
d. to fall
13. The fluid is said to be incompressible, if its density is:
a. Very small
b. zero
c. Constant
d. very high
14. Let A= Area of crossection of Pipe, v=speed of fluid then ‘A’ is called:
a. Mass flow rate
b. Volume flow rate
c. Pressure flow rate
d. Energy flow rate
15. When water falls from tap, its cross-sectional area decrease due to:
a. Air pressure
b. Decrease of speed
c. Gravity increase
d. Increase of speed
16. The dimensions of gh has same as that of:
a. Pressure
b. Work
c. Mass
d. Energy
17. The term 1/2pv2 in Bernoulli’s equation has the same unit as:
a. Pressure
b. Work
c. Force
d. Volume
18. Identify the correct answer. What do you know infer from Bernoulli’s theorem?
a. This theorem is valid only for turbulent flow of the fluid
b. Where the speed of the fluid is high the pressure will be low
c. Where the speed of fluid is low the pressure is high
d. Where the speed of fluid is high the pressure is also high
19. The concentration of red blood cells in the blood is nearly:
a. 25%
b. 40%
c. 50%
d. 60%
20. The instrument which detects the instant at which the external pressure becomes equal to thy systolic pressure is called:
a. Barometer
b. Manometer
c. Stethoscope
d. Sphygmomanometer
21. The systolic pressure of normal healthy person is:
a. 120torr
b. 110torr
c. 130torr
d. 115torr
22. A 6.0 meter high tank is full of water. A hole appears at its middle. What is speed of efflux:
a. 7.66 ms-1
b. 5.66 ms-1
c. 8.66 ms-1
d. 6.66 ms-1
23. If the stream lines of fluid are forced closer together then:
a. Pressure of fluid increases
b. Speed of fluid increases
c. Speed of fluid remain same
d. Speed of fluid decreases
24. One torr in Nm-2 is expressed as:
a. 140.2 Nm-2
b. 130.5Nm-2
c. 135.3 Nm-2
d. 133.3 Nm-2