# Class 9 Physics Chapter 7

Updated: 29 Oct 2023

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Class 9 Physics Chapter 7 is about “Properties of Matter”. This article includes topics such as

Properties of Matter, Kinetic Molecular Model of Matter (Solids, Liquids, Gases and Plasma), Density, Pressure, Atmospheric Pressure, Measurement of Atmospheric Pressure, Atmospheric Pressure and Weather, Pascal’s Principle, Liquid, Pressure, Up thrust and Buoyancy, Archimedes Principle, Elasticity, Hooke’s Law, Stress, Strain, Young’s Modulus, Stress-Strain Curves.

## Class 9 Physics Chapter 7 Notes

### Properties of Matter Notes

Class 9 Physics Chapter 7 Notes

Download Chapter 7 Notes### Class 9 Physics Chapter 7 SLO Notes

## Class 9 Physics Chapter 7 MCQs

### Properties of Matter

1. Anything that occupy space and has mass is called,(a) Solid

(b) Liquid

(c) Gas

(d) Matter

## Show Answer

**
Matter
**

**To Download Complete Notes of Physics Notes 9 Class, Click on the given link.**

### Kinetic Molecular Model of Matter

#### Solids

#### Liquids

#### Gases

#### Plasma

2 According to the Kinetic Molecular Model of Matter, how do molecules behave in solids?(a) They move randomly

(b) They vibrate about fixed positions

(c) They flow freely

(d) They collide constantly

## Show Answer

**
They vibrate about fixed positions
**

3 In which state of matter do molecules have the least attractive forces between them?

(a) Solid

(b) Liquid

(c) Gas

(d) Plasma

## Show Answer

**
Gas
**

4 How many states of matter are?

(a) 1

(b) 2

(c) 3

(d) 4

## Show Answer

**
4
**

5 The fourth state of matter is called,

(a) Solid

(b) Liquid

(c) Gas

(d) Plasma

## Show Answer

**
Plasma
**

6 The ionized state of matter is called,

(a) Solid

(b) Liquid

(c) Gas

(d) Plasma

## Show Answer

**
Plasma
**

7 What is the main characteristic of plasma as a state of matter?

(a) Fixed molecular arrangement

(b) Strong attractive forces

(c) Presence of free electrons

(d) Constant random motion of molecules

## Show Answer

**
Presence of free electrons
**

8 Why liquids and gases are collectively referred to as fluids?

(a) Because they have a fixed shape

(b) Because they have strong intermolecular forces

(c) Because they can change their shape and flow

(d) Because they are always in a gaseous state

## Show Answer

**
Because they can change their shape and flow
**

9 Which state of matter is characterized by molecules moving rapidly in all directions and colliding with each other?

(a) Solid

(b) Liquid

(c) Gas

(d) Plasma

## Show Answer

**
Gas
**

10 What is the primary difference between the molecular arrangement in solids and liquids?

(a) Solids have no molecular arrangement, while liquids do

(b) Solids have molecules that flow freely, while liquids have fixed arrangements

(c) Solids have molecules that vibrate about fixed positions, while liquids have changing positions

(d) Solids have larger distances between molecules compared to liquids

## Show Answer

**
Solids have molecules that vibrate about fixed positions, while liquids have changing positions
**

11 In which state of matter do molecules have the largest distance between them?

(a) Solid

(b) Liquid

(c) Gas

(d) Plasma

## Show Answer

**
Gas
**

12 Where can plasma be found naturally on Earth?

(a) In everyday household items

(b) In the sun’s thermonuclear reactions

(c) In the atmosphere

(d) In deep ocean trenches

## Show Answer

**
In the sun’s thermonuclear reactions
**

13 Which state of matter is composed of free electrons and atoms with removed electrons?

(a) Solid

(b) Liquid

(c) Gas

(d) Plasma

## Show Answer

**
Plasma
**

14 What causes matter to have different states, such as solids, liquids, gases, and plasma?

(a) Magnetic properties

(b) Kinetic Molecular Theory

(c) Electrical conductivity

(d) All of these

## Show Answer

**
Kinetic Molecular Theory
**

### Density

15 The mass of a substance per unit volume, is called(a) Density

(b) Pressure

(c) Force

(d) Elasticity

## Show Answer

**
Density
**

16 Which material has the highest density?

(a) Gold

(b) Iron

(c) Mercury

(d) Ice

## Show Answer

**
Gold
**

17 What is the SI unit of density?

(a) g/cm^3

(b) kg/m^3

(c) kg/cm^3

(d) g/m^3

## Show Answer

**
kg/m^3
**

18 If a substance has a mass of 1000 kg and a volume of 2 m^3 , what is its density?

(a) 0.5 kg/m^3

(b) 2 kg/m^3

(c) 500 kg/m^3

(d) 2000 kg/m^3

## Show Answer

**
500 kg/m^3
**

19 What is the density of air in kg/m^3 ?

(a) 1.3 kg/m^3

(b) 2.0 kg/m^3

(c) 13600 kg/m^3

(d) 7.1 kg/m^3

## Show Answer

**
1.3 kg/m^3
**

20 If a rectangular metal piece has a length of 0.4 \ m , width of 0.3 \ m , and height of 0.2 \ m with a mass of 60 \ kg , what is its density?

(a) 7500 \ kg/m^3

(b) 10000 \ kg/m^3

(c) 2500 \ kg/m^3

(d) 15000 \ kg/m^3

## Show Answer

**
2500 \ kg/m^3
**

21 Density is represented by……………..

(a) P

(b) D

(c) d

(d) \rho (Rho)

## Show Answer

**
\rho (Rho)
**

22 What is the formula for calculating density?

(a) \rho = m \times V

(b) \rho = m - V

(c) \rho = \frac{m}{V}

(d) \rho = m + V

## Show Answer

**
\rho = \frac{m}{V}
**

23 What happens to the density of an object when its mass increases while keeping the volume constant?

(a) Density decreases

(b) Density remains the same

(c) Density increases

(d) Density becomes zero

## Show Answer

**
Density increases
**

24 If you have two objects with the same mass, but one has a larger volume than the other, how do their densities compare?

(a) The object with the larger volume has a higher density

(b) The object with the smaller volume has a higher density

(c) Both objects have the same density

(d) None of these

## Show Answer

**
The object with the smaller volume has a higher density
**

25 If you have a container filled with a gas and you increase the volume of the container while keeping the number of gas molecules constant, what happens to the gas’s density?

(a) The density increases

(b) The density decreases

(c) The density remains the same

(d) The density depends on the type of gas

## Show Answer

**
The density decreases
**

26 What is the density of a diamond with a mass of 0.072 \ kg and a volume of 0.00002 m^3 ?

(a) 0.36 \ kg/m^3

(b) 3.6 \ kg/m^3

(c) 36 \ kg/m^3

(d) 3600 \ kg/m^3

## Show Answer

**
3600 \ kg/m^3
**

### Pressure

27 Force per unit area, is called(a) Pressure

(b) Density

(c) Energy

(d) Work

## Show Answer

**
Pressure
**

28 What is the SI unit of pressure?

(a) Newton \ (N)

(b) Pascal \ (Pa)

(c) Joule \ (J)

(d) Kilogram \ (kg)

## Show Answer

**
Pascal \ (Pa)
**

29 1 Pascal is equal to……….

(a) N/m^2

(b) N

(c) Nm^2

(d) All \ of \ these

## Show Answer

**
N/m^2
**

30 Pressure is represented by……………

(a) P

(b) Pa

(c) F

(d) None \ of \ these

## Show Answer

**
P
**

31 What is the formula for calculating pressure?

(a) P = F \times A

(b) P = \frac{F}{A}

(c) P = \frac{A}{F}

(d) None \ of \ these

## Show Answer

**
P = \frac{F}{A}
**

32 How does pressure change when the force applied to an area increases?

(a) Pressure increases

(b) Pressure decreases

(c) Pressure remains constant

(d) Pressure becomes zero

## Show Answer

**
Pressure increases
**

33 If the force acting on a surface is doubled while keeping the area constant, what happens to the pressure?

(a) Pressure halves

(b) Pressure doubles

(c) Pressure remains the same

(d) Pressure becomes zero

## Show Answer

**
Pressure doubles
**

34 What happens to pressure when the area over which a force is distributed is increased?

(a) Pressure decreases

(b) Pressure remains the same

(c) Pressure increases

(d) Pressure becomes zero

## Show Answer

**
Pressure decreases
**

35 If the area of contact is reduced by half while keeping the force constant, what happens to the pressure?

(a) Pressure halves

(b) Pressure doubles

(c) Pressure remains the same

(d) Pressure becomes zero

## Show Answer

**
Pressure doubles
**

36 Why does a needle popping a balloon exert more pressure than a finger pressing on it?

(a) The needle has a smaller surface area

(b) The needle has a greater force

(c) The finger is softer

(d) The needle is sharper

## Show Answer

**
The needle has a smaller surface area
**

37 Why does getting stepped on by a heeled shoe hurt more than getting stepped on by a flat one?

(a) Heeled shoes have more weight

(b) Heeled shoes have a larger surface area

(c) Smaller surface exerts greater pressure

(d) It’s due to the shape of the shoe

## Show Answer

**
Smaller surface exerts greater pressure
**

38 A force of 500 \ N is applied to an area of 10 \ m^2 . What is the pressure exerted?

(a) 5 \ N/m^2

(b) 50 \ N/m^2

(c) 5000 \ N/m^2

(d) 50,000 \ N/m^2

## Show Answer

**
50 \ N/m^2
**

39 If a 3000 \ N force is distributed over an area of 2 \ m^2 , what is the pressure?

(a) 1500 \ N/m^2

(b) 6000 \ N/m^2

(c) 150 \ N/m^2

(d) 7500 \ N/m^2

## Show Answer

**
1500 \ N/m^2
**

40 A car with a mass of 1200 \ kg exerts a downward force due to gravity. If the area of tires in contact with the ground is 0.02 \ m^2 , what is the pressure exerted by tires?

(a) 6000 \ N/m^2

(b) 30,000 \ N/m^2

(c) 588,000 \ N/m^2

(d) 3000 \ N/m^2

## Show Answer

**
588,000 \ N/m^2
**

41 A hydraulic jack applies a force of 8000 \ N to a small piston with an area of 0.01 \ m2 . What pressure is generated?

(a) 800,000 \ N/m^2

(b) 80,000 \ N/m^2

(c) 8 \ N/m^2

(d) 800 \ N/m^2

## Show Answer

**
800,000 \ N/m^2
**

42 If a book with a weight of 20 \ N rests on a shelf with an area of 0.1 \ m^2 , what is the pressure on the shelf?

(a) 2 \ N/m^2

(b) 200 \ N/m^2

(c) 2000 \ N/m^2

(d) 0.2 \ N/m^2

## Show Answer

**
200 \ N/m^2
**

### Atmospheric Pressure

43 The layer of gases that surround the Earth is called,(a) Atmosphere

(b) Atmospheric pressure

(c) Pressure

(d) Weather

## Show Answer

**
Atmosphere
**

44 The pressure exerted by atmosphere is said to be……………….

(a) Atmosphere

(b) Atmospheric pressure

(c) Pressure

(d) Weather

## Show Answer

**
Atmospheric pressure
**

45 Why do swimmers and divers feel water pressure on all parts of their bodies?

(a) Due to the force of gravity

(b) Due to their body weight

(c) Because water is a fluid and exerts pressure

(d) Because of buoyancy

## Show Answer

**
Because water is a fluid and exerts pressure
**

46 What is the pressure exerted by the atmosphere on average at sea level?

(a) 10 \ Pa

(b) 1.013 \times 10^5 \ Pa

(c) 1.013 \times 10^3 \ Pa

(d) 1.013 \times 10^6 \ Pa

## Show Answer

**
1.013 \times 10^5 \ Pa
**

47 How is standard atmospheric pressure defined in terms of the atmosphere (atm) ?

(a) 1 atm = 1 \ Pa

(b) 1 atm = 1.013 \times 10^3 \ Pa

(c) 1 atm = 1.013 \times 10^5 \ Pa

(d) 1 atm = 1.013 \times 10^6 \ Pa

## Show Answer

**
1 atm = 1.013 \times 10^5 \ Pa
**

48 What is another unit of pressure used in meteorology and weather maps?

(a) Newton (N)

(b) Bar (bar)

(c) Pascal (Pa)

(d) Atmosphere (atm)

## Show Answer

**
Bar (bar)
**

49 At high altitudes, climbers encounter lower atmospheric pressure due to what factor?

(a) Thinner air

(b) Thicker air

(c) Higher levels of oxygen

(d) Increased atmospheric pressure

## Show Answer

**
Thinner air
**

50 What happens when air is pumped out of a sealed can?

(a) The can expands

(b) The can remains unchanged

(c) The can collapses due to external atmospheric pressure

(d) None of these

## Show Answer

**
The can collapses due to external atmospheric pressure
**

51 Why do we generally not feel the atmospheric pressure on our bodies while on land?

(a) The atmosphere doesn’t exert pressure on land

(b) We are unaffected by atmospheric pressure

(c) Our bodies oppose the atmospheric pressure

(d) Atmospheric pressure is too weak to be felt

## Show Answer

**
Our bodies oppose the atmospheric pressure
**

#### Measurement of Atmospheric Pressure

52 Who is credited with inventing the mercury barometer in 1643?(a) Galileo Galilei

(b) Isaac Newton

(c) Evangelista Torricelli

(d) Johannes Kepler

## Show Answer

**
Evangelista Torricelli
**

53 What is the purpose of a mercury barometer?

(a) To measure temperature

(b) To measure humidity

(c) To measure atmospheric pressure

(d) To measure wind speed

## Show Answer

**
To measure atmospheric pressure
**

54 How does a mercury barometer work to measure atmospheric pressure?

(a) By measuring the weight of the mercury

(b) By measuring the height of the mercury column

(c) By measuring the density of the mercury

(d) By measuring the temperature of the mercury

## Show Answer

**
By measuring the height of the mercury column
**

55 At sea level, what is the typical height of the mercury column in a mercury barometer due to atmospheric pressure?

(a) 760 mm

(b) 1000 mm

(c) 500 mm

(d) 2000 mm

## Show Answer

**
760 mm
**

56 Why is it impractical to build a barometer using water instead of mercury?

(a) Water is too expensive

(b) Water is too difficult to work with

(c) Water is less dense than mercury

(d) Water reacts with air

## Show Answer

**
Water is less dense than mercury
**

57 What does any change in the height 'h' of the mercury column in a barometer indicate?

(a) Changes in temperature

(b) Changes in humidity

(c) Changes in atmospheric pressure

(d) Changes in wind direction

## Show Answer

**
Changes in atmospheric pressure
**

#### Atmospheric Pressure and Weather

58 What are the lines on weather maps that join places with the same atmospheric pressure called?(a) Isobars

(b) Isolines

(c) Isotherms

(d) None of these

## Show Answer

**
Isobars
**

59 What is the unit of pressure commonly used in weather maps?

(a) Pascal (Pa)

(b) Atmosphere (atm)

(c) Millibar (mbar)

(d) Newton per square meter (N/m^2)

## Show Answer

**
Millibar (mbar)
**

60 How is 1000 millibars (mbar) related to bar?

(a) 1000 mbar = 1 bar

(b) 1000 mbar = 2 bar

(c) 1000 mbar = 3 bar

(d) 1000 mbar = 4 bar

## Show Answer

**
1000 mbar = 1 bar
**

61 What is the approximate range of atmospheric pressure variation in millibars?

(a) 1000 mbar to 1010 mbar

(b) 1040 mbar to 950 mbar

(c) 900 mbar to 1100 mbar

(d) 950 mbar to 1050 mbar

## Show Answer

**
1040 mbar to 950 mbar
**

62 In which direction do winds generally move around the areas of high pressure?

(a) Clockwise

(b) Anticlockwise

(c) Straight up

(d) Straight down

## Show Answer

**
Clockwise
**

63 In which direction do winds generally move around the areas of low pressure?

(a) Clockwise

(b) Anticlockwise

(c) Straight up

(d) Straight down

## Show Answer

**
Anticlockwise
**

64 What determines the strength of the wind?

(a) Wind direction

(b) Atmospheric humidity

(c) Pressure gradient

(d) Temperature difference

## Show Answer

**
Pressure gradient
**

65 What happens when isobars are closely packed together on a weather map?

(a) It indicates calm weather

(b) It suggests a high-pressure gradient and the potential for strong winds

(c) It signifies low atmospheric pressure

(d) It represents an approaching storm

## Show Answer

**
It suggests a high-pressure gradient and the potential for strong winds
**

### Pascal’s Principle

66 An external pressure applied to an enclosed fluid is transmitted unchanged to every point within the fluid, is called(a) Pascal’s principle

(b) Archimedes principle

(c) Hooke’s law

(d) Young’s modulus

## Show Answer

**
Pascal’s principle
**

67 If the ratio \frac{A_1}{A_2} \ is \ 100 in a hydraulic lift, and a force F_1 is applied to piston 1, what force F_2 is exerted on piston 2?

(a) F_1

(b) 100F_1

(c) 10F_1

(d) \frac{F_1}{100}

## Show Answer

**
100F_1
**

68 In a hydraulic system, if you apply a small force to a piston with a small surface area, what happens to the force applied to the larger piston with a greater surface area?

(a) It decreases

(b) It remains the same

(c) It increases

(d) None of these

## Show Answer

**
It increases
**

69 How can Pascal’s principle be applied to lift heavy objects with ease?

(a) By using a lever

(b) By using a hydraulic system with a smaller and larger piston

(c) By increasing the size of the container

(d) By increasing the density of the fluid

## Show Answer

**
By using a hydraulic system with a smaller and larger piston
**

70 If you push down with a force of 10 \ N on a small piston with an area of 0.01 \ m^2 in a hydraulic system, and the larger piston has an area of 0.1 \ m^2 , what force is exerted on the larger piston?

(a) 100 \ N

(b) 0.1 \ N

(c) 1 \ N

(d) 10 \ N

## Show Answer

**
100 \ N
**

71 What is the practical application of Pascal’s principle?

(a) Pumping air into a bicycle tire

(b) Blowing up a balloon

(c) Driving a car

(d) Both (a) & (b)

## Show Answer

**
Both (a) & (b)
**

72 In the formula F_2 = \frac{A_2}{A_1} \times F_1 , what does F_2 represent?

(a) Force applied on the smaller piston

(b) Force applied on the larger piston

(c) Force applied on both pistons

(d) None of these

## Show Answer

**
Force applied on the larger piston
**

73 According to the formula F_2 = \frac{A_2}{A_1} \times F_1, how does the force on piston 2 (F_2) change with respect to the area of piston 1 (A_1) ?

(a) F_2 decreases as A_1 increases

(b) F_2 increases as A_1 increases

(c) F_2 remains constant regardless of A_1

(d) F_2 is not related to A_1

## Show Answer

**
F_2 decreases as A_1 increases
**

74 If you apply a force of 20 \ N on a piston with an area of 0.02 \ m^2 (A_1) , and the second piston (A_2) has an area of 0.04 \ m^2, what will be the force (F_2) applied on the second piston according to the formula F_2 = \frac{A_2}{A_1} \times F_1 ?

(a) 10 N

(b) 20 N

(c) 30 N

(d) 40 N

## Show Answer

**
40 N
**

75 Which parameter(s) in the formula F_2 = \frac{A_2}{A_1} \times F_1 can be adjusted to increase the force F_2 in a hydraulic system?

(a) A_1 only

(b) A_2 only

(c) Both A_1 \ and \ A_2

(d) Neither A_1 \ nor \ A_2

## Show Answer

**
Both A_1 \ and \ A_2
**

76 Why does the pressure increase with depth in a fluid?

(a) Because liquids are incompressible

(b) Because liquids have varying densities

(c) Because liquids are highly viscous

(d) None of these

## Show Answer

**
Because liquids are incompressible
**

### Liquid Pressure

77 What is the formula for pressure (P) in a liquid at a certain depth (h) below the surface, considering the density of the liquid (\rho) and acceleration due to gravity (g)?(a) P = \rho h

(b) P = \rho gh

(c) P = \rho Ahg

(d) P = mg

## Show Answer

**
P = \rho gh
**

78 According to the properties of liquids and pressure, what happens to the pressure in a liquid as you go deeper below the surface?

(a) It decreases

(b) It remains constant

(c) It increases

(d) None of these

## Show Answer

**
It increases
**

79 What principle explains why the pressure at the bottom of a liquid depends only on its vertical depth and not on the shape or width of the container?

(a) Archimedes’ principle

(b) Pascal’s principle

(c) Hooke’s law

(d) All of these

## Show Answer

**
Pascal’s principle
**

80 What is the pressure at the bottom of a swimming pool that is 5 \ meters deep?

(a) 49,000 \ Pa

(b) 500 \ Pa

(c) 9.8 \ Pa

(d) 5 \ Pa

## Show Answer

**
49,000 Pa
**

### Upthrust and Buoyancy

81 The force that acts on an object immersed in a fluid due to the difference in pressures on its upper and lower surfaces is called,(a) Weight

(b) Buoyant force

(c) Normal

(d) Pressure gradient

## Show Answer

**
Buoyant force
**

82 The buoyant force is also known as,

(a) Upthrust

(b) Buoyancy

(c) Weight

(d) All of these

## Show Answer

**
Upthrust
**

83 The phenomena in which a buoyant force act on an object is called,

(a) Upthrust

(b) Buoyancy

(c) Weight

(d) All of these

## Show Answer

**
Buoyancy
**

### Archimedes Principle

84 The buoyant force on an object is equal to the weight of the fluid it displaces is called,(a) Archimedes’ principle

(b) Pascal’s principle

(c) Hooke’s law

(d) All of these

## Show Answer

**
Archimedes’ principle
**

85 Why does a wooden block float when placed in water, as described by Archimedes’ principle?

(a) The block is denser than water

(b) The block’s weight is greater than the buoyant force

(c) The block’s weight is less than the buoyant force

(d) The block’s volume is small

## Show Answer

**
The block’s weight is less than the buoyant force
**

86 How does a hydrometer work to measure the density of a liquid?

(a) It measures the liquid’s volume

(b) It compares the liquid’s color to a reference chart

(c) It measures the liquid’s weight

(d) It measures how deep it sinks in the liquid

## Show Answer

**
It measures how deep it sinks in the liquid
**

87 Why does a helium-filled balloon rise in the air when released?

(a) Helium is denser than air

(b) The balloon is heavy

(c) Air is lighter than helium

(d) Air is denser than helium

## Show Answer

**
Air is denser than helium
**

88 Why does an object float in a fluid according to Archimedes’ Principle?

(a) The object’s weight is greater than the buoyant force

(b) The object’s volume is greater than the fluid’s volume

(c) The object’s density is less than the fluid’s density

(d) The object’s density is greater than the fluid’s density

## Show Answer

**
The object’s density is less than the fluid’s density
**

89 If an object is fully submerged in water and experiences an upthrust equal to its weight, what is its net force?

(a) Zero

(b) Greater than its weight

(c) Equal to its weight

(d) Less than its weight

## Show Answer

**
Zero
**

90 When will an object sink in a fluid?

(a) When W = F_B

(b) When W < F_B

(c) When W > F_B

(d) When W is unrelated to F_B

## Show Answer

**
When W > F_B
**

91 When will an object float in a fluid?

(a) When W = F_B

(b) When W < F_B

(c) When W > F_B

(d) When W is unrelated to F_B

## Show Answer

**
When W < F_B
**

92 What happens to an object when W = F_B in a fluid?

(a) The object sinks

(b) The object floats

(c) The object remains suspended

(d) None of these

## Show Answer

**
The object remains suspended
**

93 When is an object in neutral buoyancy in a fluid?

(a) When W = F_B

(b) When W < F_B

(c) When W > F_B

(d) When W is unrelated to F_B

## Show Answer

**
When W = F_B
**

### Elasticity

94 What property of solid materials allows them to return to their original shape and size after the removal of a deforming force?(a) Plasticity

(b) Elasticity

(c) Brittleness

(d) Rigidity

## Show Answer

**
Elasticity
**

95 When an archer shoots an arrow, what property of the bow allows it to return to its original form after the arrow is released?

(a) Plasticity

(b) Elasticity

(c) Brittleness

(d) Rigidity

## Show Answer

**
Elasticity
**

96 What is the term for materials that do not return to their original shapes when a deforming force is removed?

(a) Elastic

(b) Inelastic

(c) Plastic

(d) Rigid

## Show Answer

**
Inelastic
**

97 What is the limit beyond which a material will not return to its original dimensions and may break or permanently deform?

(a) Plastic limit

(b) Elastic limit

(c) Inelastic limit

(d) Rigidity limit

## Show Answer

**
Elastic limit
**

### Hooke’s Law

98 Within elastic limit, the extension or compression is directly proportional to the restoring force is called,(a) Pascal’s principle

(b) Archimedes’ principle

(c) Hooke’s law

(d) None of these

## Show Answer

**
Hooke’s law
**

99 In Hooke’s Law, what does ‘k’ represent?

(a) The displacement of the spring

(b) The restoring force of the spring

(c) The velocity of the spring

(d) The force constant of the spring

## Show Answer

**
The force constant of the spring
**

100 What are the units of the force constant 'k' in Hooke’s Law?

(a) N/m

(b) Ns

(c) N/kg

(d) m/s

## Show Answer

**
N/m
**

101 Hooke’s Law describes the behavior of springs within what limits?

(a) Inelastic limits

(b) Elastic limits

(c) Plastic limits

(d) Rigidity limits

## Show Answer

**
Elastic limits
**

102 In Hooke’s Law, what does the negative sign represent?

(a) It indicates a loss of energy

(b) It signifies an increase in temperature

(c) It shows the force is directed against the displacement

(d) It denotes a decrease in the spring constant

## Show Answer

**
It shows the force is directed against the displacement
**

103 Which mathematical expression represents Hooke’s Law for a spring under extension or compression?

(a) F = kx

(b) F = \frac{k}{x}

(c) F = kx^2

(d) All \ of \ these

## Show Answer

**
F = kx
**

### Stress

104 What is stress in a material?(a) The extension per unit length

(b) The force applied per unit area

(c) The deformation produced in a wire

(d) The ratio of stress to strain

## Show Answer

**
The force applied per unit area
**

105 Stress is typically denoted by:

(a) S

(b) T

(c) \sigma (sigma)

(d) \epsilon (epsilon)

## Show Answer

**
\sigma (sigma)
**

106 Which formula correctly defines stress?

(a) Stress = \frac{Force}{Extension}

(b) Stress = \frac{Extension}{Original \ Length}

(c) Stress = \frac{Force}{Area \ of \ Cross-Section}

(d) Stress = \frac{Area \ of \ Cross-Section}{Force}

## Show Answer

**
Stress = \frac{Force}{Area \ of \ Cross-Section}
**

107 What is the unit of stress?

(a) N/m

(b) kg/m^3

(c) N/m^2

(d) m/s^2

## Show Answer

**
N/m^2
**

108 Which unit is used to express stress in the International System of Units (SI)?

(a) Newton (N)

(b) Pascal (Pa)

(c) Joule (J)

(d) Kilogram (kg)

## Show Answer

**
Pascal (Pa)
**

109 A load of 8000 N is distributed over an area of 4 \ m^2 . Find the stress on the surface.

(a) 2000 N/m^2

(b) 3000 N/m^2

(c) 4000 N/m^2

(d) 5000 N/m^2

## Show Answer

**
2000 N/m^2
**

### Strain

110 The extension per unit length, is called(a) Stress

(b) Strain

(c) Young’s modulus

(d) All of these

## Show Answer

**
Strain
**

111 Strain is commonly represented by the symbol:

(a) E

(b) S

(c) \eta (eta)

(d) \epsilon (epsilon)

## Show Answer

**
\epsilon (epsilon)
**

112 What is the formula for strain?

(a) Strain = \frac{Force}{Area}

(b) Strain = \frac{Extension}{Original \ Length}

(c) Strain = Stress \times Area

(d) Strain = \frac{Young's \ Modulus}{Stress}

## Show Answer

**
Strain = \frac{Extension}{Original \ Length}
**

113 What is the unit of strain?

(a) Nm^2

(b) Pascal (Pa)

(c) Newton (N)

(d) It doesn’t have a unit

## Show Answer

**
It doesn’t have a unit
**

114 If the extension of a material is 0.02 \ meters , and the original length is 0.01 \ meters , what is the strain?

(a) 0.002

(b) 0.2

(c) 5

(d) 2

## Show Answer

**
2
**

### Young’s Modulus

115 The ratio of stress to strain, is said to be,(a) Stress

(b) Strain

(c) Young’s modulus

(d) All of these

## Show Answer

**
Young’s modulus
**

116 Young’s modulus is represented by…………..

(a) Y

(b) YM

(c) S

(d) F

## Show Answer

**
Y
**

117 What is the formula for Young’s Modulus (Y) ?

(a) Y = \frac{Stress}{Strain}

(b) Y = \frac{Strain}{Stress}

(c) Y = \frac{Force}{Area}

(d) Y = \frac{Extension}{Original \ Length}

## Show Answer

**
Y = \frac{Stress}{Strain}
**

118 What is the unit of Young’s Modulus?

(a) Newton (N)

(b) Second (s)

(c) Joule (J)

(d) Newton per meter squared (N/m^2)

## Show Answer

**
Newton per meter squared (N/m^2)
**

119 When stress and strain are plotted on a graph, the slope of the linear region represents:

(a) Elastic limit

(b) Proportional limit

(c) Yield point

(d) Breaking point

## Show Answer

**
Proportional limit
**

120 If a material has a stress of 500 \ Pa and a strain of 5 , what is its Young’s Modulus?

(a) 100 N/m^2

(b) 10 N/m^2

(c) 25 N/m^2

(d) 5 N/m^2

## Show Answer

**
100 N/m^2
**

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