Turning Effect of Forces – Online MCQs Test – Physics 9th

1. Bunsen burner is made stable by:

increasing its mass

increasing its base area

increasing its length

decreasing its base area

2. sin θ =:

perpendicular / hypotenuse

base / hypotenuse

perpendicular / base

base / hypotenuse

3. A body is in equilibrium when it has:

uniform speed and uniform acceleration

uniform acceleration

zero acceleration

uniform speed

4. A pair of unlike parallel forces having different lines of force produce _________:

a couple

equilibrium

torque

unstable equilibrium

5. A wall hanging, buildings, bridges or any object lying in rest on the ground are some examples of:

dynamic equilibrium

inertia

acceleration due to gravity

static equilibrium

6. States of equilibrium are:

four

two

five

three

7. According to the second condition for equilibrium:

sum of the all forces acting on a body must be equal to zero

sum of all torques acting on a body is zero

sum of all torques acting on a body is constant

sum of the all, forces acting on a body must be constant

8. S.I unit of the torque or moment of force is:

Newton second

Newton metre

Newton per second

Newton

9. The following expression represents:

Newton’s first Law of motion

the first condition of equilibrium

Newton’s second law of motion

the second condition of equilibrium

10. The turning effect of force is called:

moment of force and torque

none of these

moment of force

torque

11. If a body is slightly titled and does not return back to its previous position, the body is said to be in:

unstable equilibrium

neutral equilibrium

stable equilibrium

none of these

12. Head to tail rule can be used to add_______ forces.

two

five

three

any number of

13. Force has:

both magnitude and direction

only direction

none of these

only magnitude

14. When a body is slightly displaced and then released it returns to its previous position then the equilibrium will be:

neutral equilibrium

stable equilibrium

unstable equilibrium

None of these

15. A body is in neutral equilibrium when its center of gravity:

is at the lowest position

is at its base

remains at same height

is at highest position

16. A force of 15 N makes an angle of 60 with horizontal. Its vertical component will be:

10N

13N

15N

17. Graphical method is used for addition of:

one dimensional vector quantities

three dimensional vector quantities

all of these

two dimensional vector quantities

18. Stability of a racing car is increased by:

increasing its height

raising its centre of gravity

lowering its centre of gravity

decreasing its width

19. A body must satisfy __________ conditions to be in equilibrium.

five

four

two

three

20. A paratrooper moving down with terminal velocity satisfies:

the second condition of equilibrium

Law of gravitation

the first condition of equilibrium

Newton’s second law of motion

Class 9th | Physics | Chapter 4 | Turning Effect of Forces | Online MCQs Test