physics MCQs - 11th class Chapter 06 Mcqs

1

The frictional effect between different layers of a flowing fluid is described in terms of?

A

Drag

B

Viscosity

C

Turbulence

D

Pressure

2

According to the PDF, a retarding force on an object moving through a fluid is called?

A

Viscous force

B

Net force

C

Drag force

D

Upthrust

3

Stokes' law, F = 6πηrv, is specifically for a ___ moving slowly through a fluid.

A

Cylinder

B

Cube

C

Sphere

D

Flat plate

4

An object falling through a viscous fluid reaches terminal velocity when?

A

Its weight is zero

B

The drag force equals its weight

C

Its acceleration is maximum

D

The viscous force is zero

5

The formula for terminal velocity shows it is directly proportional to the ___ of the radius of the object.

A

Square root

B

Cube

C

Square

D

Value

6

A flow in which every particle passing a point moves along the same path is called?

A

Turbulent flow

B

Irregular flow

C

Unsteady flow

D

Streamline flow

7

The irregular and unsteady flow of a fluid, where streamlines may cross, is known as?

A

Laminar flow

B

Turbulent flow

C

Ideal flow

D

Incompressible flow

8

Which of the following is NOT a characteristic of an ideal fluid as per the text?

A

Incompressible

B

Non-viscous

C

Steady flow

D

Compressible

9

The equation of continuity (A₁v₁ = A₂v₂) is a direct consequence of the law of conservation of?

A

Energy

B

Momentum

C

Charge

D

Mass

10

In the equation of continuity, if the cross-sectional area of a pipe decreases, the fluid speed must?

A

Decrease

B

Remain constant

C

Increase

D

Become zero

11

Bernoulli's equation (P + ½ρv² + ρgh = constant) is based on the principle of?

A

Conservation of mass

B

Conservation of energy

C

Conservation of momentum

D

Newton's second law

12

According to Bernoulli's principle, in a region where fluid speed is high, the pressure is?

A

High

B

Low

C

Constant

D

Zero

13

Torricelli's theorem, v₂ = √2g(h₁-h₂), is used to calculate the speed of?

A

A falling ball

B

Efflux from an orifice

C

A moving car

D

Sound in air

14

The upward lift on an aeroplane wing is created because the air speed is ___ above the wing compared to below it.

A

Slower

B

The same

C

Faster

D

Irrelevant

15

A Venturimeter is a device designed to measure the?

A

Pressure of a fluid

B

Density of a fluid

C

Speed of a fluid

D

Viscosity of a fluid

16

The 'swing' of a spinning ball is a practical application of?

A

Stokes' Law

B

Equation of Continuity

C

Torricelli's Theorem

D

Bernoulli's Effect

17

The text states that blood is an ___ fluid with a density nearly equal to that of water.

A

Incompressible

B

Ideal

C

Non-viscous

D

Gaseous

18

The high pressure in the arteries during heartbeats is known as?

A

Diastolic pressure

B

Atmospheric pressure

C

Systolic pressure

D

Gauge pressure

19

For a normal healthy person, the systolic pressure is approximately?

A

80 torr

B

100 torr

C

120 torr

D

150 torr

20

The instrument used to dynamically measure blood pressure is the?

A

Venturimeter

B

Thermometer

C

Stethoscope

D

Sphygmomanometer

21

The term ½ρv² in Bernoulli's equation represents?

A

Pressure energy

B

Potential energy per unit volume

C

Kinetic energy per unit volume

D

Work done

22

The term ρgh in Bernoulli's equation represents?

A

Kinetic energy

B

Pressure

C

Potential energy per unit volume

D

Flow rate

23

The operation of a perfume atomizer or a paint sprayer relies on?

A

Torricelli's theorem

B

Stokes' law

C

Bernoulli's principle

D

Archimedes' principle

24

When streamlines are forced closer together, what happens to the fluid speed?

A

It decreases

B

It remains the same

C

It becomes turbulent

D

It is faster

25

Blood viscosity is how many times greater than water's viscosity?

A

1 to 2 times

B

3 to 5 times

C

10 times

D

Same as water

26

A chimney works best when exposed to air currents because the wind?

A

Increases pressure at the top

B

Reduces pressure at the top

C

Stops the smoke

D

Heats the chimney

27

For flow from a large pipe to a small pipe, the Venturi relation neglects which term?

A

Initial speed (v₁)

B

Final speed (v₂)

C

Pressure (P₁)

D

Density (ρ)

28

What causes the retarding force on a car traveling at high speed?

A

The small viscosity of the air

B

The car's weight

C

The road friction only

D

Gravity

29

According to the table, which substance has the highest viscosity at 30°C?

A

Water

B

Air

C

Plasma

D

Glycerin

30

The unit 'torr' is used for blood pressure due to its extensive use in?

A

Physics laboratories

B

Weather forecasting

C

Medical equipment

D

Engineering

31

In laminar flow, layers of fluid slide ___ past each other.

A

Roughly

B

Smoothly

C

Turbulently

D

Randomly

32

The product of cross-sectional area and fluid speed (Av) is also known as?

A

Mass flow rate

B

Pressure

C

Volume flow rate

D

Density

33

As water falls from a tap, its speed increases, and its cross-sectional area?

A

Increases

B

Remains constant

C

Decreases

D

Expands and contracts

34

If a fluid is stationary, Bernoulli's equation simplifies to relate only?

A

Pressure and speed

B

Speed and height

C

Pressure and height

D

Speed and density

35

A stethoscope helps measure blood pressure by detecting the sound of ___ flow.

A

Laminar

B

Ideal

C

Steady

D

Turbulent

36

The low pressure between heart beats is known as?

A

Systolic pressure

B

Diastolic pressure

C

Mean pressure

D

Absolute pressure

37

For a normal healthy person, the diastolic pressure is in the range of?

A

50-60 torr

B

75-80 torr

C

90-100 torr

D

120-130 torr

38

In Stokes' Law F=6πηrv, the symbol 'η' represents?

A

Radius

B

Density

C

Viscosity

D

Velocity

39

The conservation of mass and conservation of ___ are the two principles that simplify fluid dynamics.

A

Momentum

B

Charge

C

Energy

D

Viscosity

40

The density of a fluid is assumed to be ___ in an incompressible flow.

A

Zero

B

Variable

C

Constant

D

Infinite

41

If an orifice on a water tank is pointed upward, the kinetic energy of the efflux would allow the liquid to rise to the?

A

Level of the orifice

B

Level of the water tank

C

Half the tank height

D

Twice the tank height

42

An airplane wing is designed to deflect air so that streamlines are closer together ___ the wing.

A

Below

B

In front of

C

Behind

D

Above

43

When external pressure applied to an arm is larger than systolic pressure, the blood vessels?

A

Expand

B

Burst

C

Collapse

D

Remain unchanged

44

The disappearance of the 'gurgle' sound in a stethoscope indicates that the external pressure equals the?

A

Systolic pressure

B

Diastolic pressure

C

Average pressure

D

Atmospheric pressure

45

The Venturi effect describes the decrease in pressure with an increase in?

A

Height

B

Density

C

Speed

D

Viscosity

46

The speed of efflux from a tank is the same as a ball falling through a height of?

A

(h₁ + h₂)

B

(h₁ - h₂)

C

(h₁ * h₂)

D

(h₁ / h₂)

47

A streamlined body, like that of a dolphin, helps to?

A

Increase drag

B

Assist movement in water

C

Increase turbulence

D

Increase weight

48

The volume of a sphere is given by the formula?

A

πr²

B

4πr²

C

(4/3)πr³

D

2πr

49

In Example 6.2, the mass flow per second is calculated as?

A

0.5 kgs⁻¹

B

1.6 kgs⁻¹

C

30 kgs⁻¹

D

60 kgs⁻¹

50

The two main applications of fluid dynamics discussed in the chapter's introduction are in aeroplanes and?

A

Weather systems

B

Blood circulation

C

Car engines

D

Hydraulic lifts