Physics 9 Unit 4 MCQs Tests

In this post, we have prepared 3 MCQs tests of Federal Board Physics 9 Unit 4 MCQs Tests.

Physics 9 Unit 4 MCQs Tests

Practice MCQs Test No 1

20

Class 9 Physics
Unit 4
Practice MCQs Test No 1

1 / 10

A body is said to be in equilibrium if:

Its velocity is not changing

Its acceleration is uniform

Its velocity is changing

Its acceleration is not uniform

2 / 10

Torque depends on:

Both Force and Moment arm

Force  

Acceleration                  

Moment arm

The formula of torque is:

Torque = Force ×  Moment arm

So torque depends on both Force and moment arm.

3 / 10

Head to tail rule is a:

Used for vector addition

Graphical method

All are correct

Used for addition of forces

4 / 10

A point where the whole weight of the body appears to act vertically downward is called:

Centre of gravity

Torque

Moment arm

Centre of mass

Weight is related to gravity so correct answer is center of gravity.

5 / 10

The number of forces that can be added by head to tail rule is:

2

3

3

Any number

6 / 10

SI unit of torque is:

joule

meter per second

newton

newton-meter

Torque  =  Force × Moment arm

Torque   =  newton-meter

7 / 10

A pencil just balanced at its tip is in ________.

Stable Equilibrium

Unstable Equilibrium

Neutral Equilibrium

Dynamic Equilibrium

Pencil will not come back to its previous position so it is unstable equilibrium.

8 / 10

Forces that are parallel to each other and have the same direction are called:

Parallel forces

Unparallel forces

Unlike parallel forces

Like parallel forces

Same direction means like

and opposite direction means unlike

9 / 10

Centre of gravity of a uniform triangular sheet lies at the point of intersection of its:

Lines   

Medians              

Corners     

Diagonals

10 / 10

A body is in equilibrium when its:

Speed is uniform

Acceleration is zero

Speed and acceleration both are uniform

Acceleration is uniform

Your score is

Practice MCQs Test No 2

18

Class 9 Physics
Unit 4
Practice MCQs Test No 2

1 / 10

When a body is in unstable equilibrium, its center of gravity:

all are correct

is at the lowest position

is at its highest position

remains at the same height

2 / 10

The number of perpendicular components of a force are:

2

4

1

3

There are two perpendicular components :

Horizontal component Fx

and vertical component Fy

3 / 10

When a body is in neutral equilibrium, its center of gravity:

remains at the same height

is at the lowest position

is at its highest position

all are correct

4 / 10

The centre of gravity of triangular-shaped body is:

The point of intersection of altitudes

The point of intersection of its medians

The centre of triangle

The point of intersection of its diagonals

Use formula   Fy = F Sin θ

5 / 10

If F=200N and θ=30°  with horizontal then what will be the value of F_y?

100 N

173.2 N

50 N

200 N

Fy = F Sinθ

Fy = 200 × Sin 30°

Fx = 200 × 0.5

Fx = 100 N

Use formula   Fx = F Cos θ

6 / 10

If F=200N and θ=30°  with horizontal then what will be the value of F_x?

100 N

173.2 N 

200 N 

50 N 

Fx = F Cosθ

Fx = 200 × Cos 30°

Fx = 200 × 0.866

Fx = 173.2 N

7 / 10

When a body is in stable equilibrium, its center of gravity:

is at its highest position

is at the lowest position

all are correct

remains at the same height

Find Fy

Force along x-axis means θ=0°

8 / 10

A force of 10 N is acting along x-axis. Its vertical component will be:

Zero

10 N

20 N

0.5 N

Fy = F Sin θ

Fy = 10 Sin 0°

Fy = 10 (0)  =   0 N

9 / 10

A racing car is made stable by:

Lowering its centre of gravity

Increasing its speed  

Decreasing its mass

Decreasing its width

For stable equilibrium center of gravity must be at the lowest position.

10 / 10

Two equal but unlike parallel forces having different line of action produce:

a couple

equilibrium

neutral equilibrium

a torque

Your score is

Challenge MCQs Test

23

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Class 9 Physics
Unit 4
Full Chapter Challenge Test

Find Fy

Force along x-axis means θ=0°

1 / 20

A force of 10 N is acting along x-axis. Its vertical component will be:

Zero

10 N

20 N

0.5 N

Fy = F Sin θ

Fy = 10 Sin 0°

Fy = 10 (0)  =   0 N

2 / 20

The centre of gravity of triangular-shaped body is:

The point of intersection of its medians

The centre of triangle

The point of intersection of its diagonals

The point of intersection of altitudes

3 / 20

The number of forces that can be added by head to tail rule is:

Any number

3

2

3

4 / 20

When a body is in neutral equilibrium, its center of gravity:

remains at the same height

all are correct

is at its highest position

is at the lowest position

5 / 20

A racing car is made stable by:

Decreasing its mass

Decreasing its width

Increasing its speed  

Lowering its centre of gravity

For stable equilibrium center of gravity must be at the lowest position.

Use formula   Fy = F Sin θ

6 / 20

If F=200N and θ=30°  with horizontal then what will be the value of F_y?

100 N

173.2 N

200 N

50 N

Fy = F Sinθ

Fy = 200 × Sin 30°

Fx = 200 × 0.5

Fx = 100 N

7 / 20

A pencil just balanced at its tip is in ________.

Stable Equilibrium

Dynamic Equilibrium

Unstable Equilibrium

Neutral Equilibrium

Pencil will not come back to its previous position so it is unstable equilibrium.

8 / 20

SI unit of torque is:

newton-meter

joule

newton

meter per second

Torque  =  Force × Moment arm

Torque   =  newton-meter

9 / 20

The number of perpendicular components of a force are:

3

2

4

1

There are two perpendicular components :

Horizontal component Fx

and vertical component Fy

10 / 20

A body is said to be in equilibrium if:

Its acceleration is not uniform

Its velocity is not changing

Its acceleration is uniform

Its velocity is changing

11 / 20

Forces that are parallel to each other and have the same direction are called:

Unparallel forces

Unlike parallel forces

Parallel forces

Like parallel forces

Same direction means like

and opposite direction means unlike

12 / 20

When a body is in unstable equilibrium, its center of gravity:

remains at the same height

is at the lowest position

is at its highest position

all are correct

13 / 20

Head to tail rule is a:

Graphical method

All are correct

Used for addition of forces

Used for vector addition

14 / 20

A point where the whole weight of the body appears to act vertically downward is called:

Torque

Centre of mass

Moment arm

Centre of gravity

Weight is related to gravity so correct answer is center of gravity.

15 / 20

A body is in equilibrium when its:

Speed and acceleration both are uniform

Acceleration is uniform

Speed is uniform

Acceleration is zero

16 / 20

Torque depends on:

Moment arm

Force  

Both Force and Moment arm

Acceleration                  

The formula of torque is:

Torque = Force ×  Moment arm

So torque depends on both Force and moment arm.

17 / 20

When a body is in stable equilibrium, its center of gravity:

is at its highest position

remains at the same height

is at the lowest position

all are correct

18 / 20

Centre of gravity of a uniform triangular sheet lies at the point of intersection of its:

Medians              

Diagonals

Lines   

Corners     

19 / 20

Two equal but unlike parallel forces having different line of action produce:

neutral equilibrium

equilibrium

a couple

a torque

Use formula   Fx = F Cos θ

20 / 20

If F=200N and θ=30°  with horizontal then what will be the value of F_x?

100 N

50 N 

200 N 

173.2 N 

Fx = F Cosθ

Fx = 200 × Cos 30°

Fx = 200 × 0.866

Fx = 173.2 N

Your score is