This post contains 9th Class Physics Notes of 4th Chapter. In this post you will find 9th Class physics Chapter 4 MCQs for students. Name of the 4th Chapter in the Physics of class 9 is “Turning Effect of Forces”. These Multiple Choice Questions are available here for Students to practice for exams.

## Turning effect of Forces: 9th Class Physics Chapter 4 MCQs for Students

You may also like: MCQs of Chapter 3 – MCQs of Chapter 5

#### 1. The number of perpendicular components of a force is:

(a) 1

(b) 3

(c) 4

(d) 2

#### 2. A force of 10N is making an angle of *30*° with horizontal. Its horizontal component will be:

(a) 4N

(b) 5N

(c) 7N

(d) 8.7N

#### 3. Turning effect of a force is called:

(a) Torque

(b) Moment

(c) Couple

(d) Torque and momentum

#### 4. If Fy = 4N and Fx = 3N, what is magnitude of resultant force:

(a) 7N

(b) 5N

(c) 12N

(d) 10N

#### 5. First condition of equilibrium is:

(a) ΣF = 0

(b) Στ = 0

(c) ΣF = 0, Στ = 0

(d) All of These

#### 6. Center of gravity of sphere is at:

(a) Centre of sphere

(b) Outside of sphere

(c) Radius of sphere

(d) none of these

#### 7. The number of forces that can be added by head to tail rule are:

(a) 2

(b) 3

(c) 4

(d) Any number

#### 8. A body is in equilibrium when its:

(a) Acceleration is uniform

(b) Speed and acceleration are uniform

(c) Speed is uniform

(d) Acceleration is non-uniform

#### 9. Formula for the direction of resultant force with the help of rectangular components.

(a) 𝛳 = tan-¹ fx/fy

(b) 𝛳 = tan-¹ fy/fx

(c) 𝛳 = sin-¹ fy/fx

(d) 𝛳 = cos-¹ fy/fx

#### 10. A force of 10N makes an angle of *90*° with x-axis. Its horizontal component will be:

(a) 10N

(b) 5N

(c) Zero

(d) Maximum

#### 11. The Conditions of equilibrium are:

(a) 1

(b) 2

(c) 3

(d) 4

#### 12. The states of equilibrium are:

(a) 1

(b) 2

(c) 3

(d) 4

#### 13. Complete equation Fᵧ/Fₓ = _________.

(a) sin 𝛳

(b) cos 𝛳

(c) tan 𝛳

(d) cosec 𝛳

#### 14. Racing cars are made stable by:

(a) Increasing their speed

(b) Decreasing their speed

(c) Decreasing their width

(d) Lowering their centre of gravity

#### 15. The direction of resultant vector can be found by:

(a) 𝛳 = tan fx/fy

(b) 𝛳 = tan fy/fx

(c) 𝛳 = tan-¹ fx/fy

(d) 𝛳 = tan-¹ fy/fx

#### 16. The value of gravitational acceleration “g” on the surface of moon is:

(a) 1.62 ms-²

(b) 3.7 ms-²

(c) 9.8 ms-²

(d) 10 ms-²

#### 17. The value of “g” at a hight one Earth’s radius above the surface of the Earth is:

(a) 2 g

(b) 1/2 g

(c) 1/3 g

(d) 1/4 g

9th Class Physics Chapter 4 Short Questions and Answers are also available.