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

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

None of these

unstable equilibrium

neutral equilibrium

stable equilibrium

2. According to the second condition for equilibrium:

sum of all torques acting on a body is constant

sum of all torques acting on a body is zero

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

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

3. They form a couple.

two Like parallel forces of the same magnitude not acting along the same line

two unlike parallel forces of the same magnitude not acting along the same line

two Like parallel forces of the same magnitude acting along the same line

two unlike parallel forces of the same magnitude acting along the same line

4. To form a couple, two forces must be:

equal in magnitude

separated by a distance

all of these

parallel, but opposite in direction

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

a couple

equilibrium

torque

unstable equilibrium

6. A body is in equilibrium when it has:

uniform speed and uniform acceleration

zero acceleration

uniform acceleration

uniform speed

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

inertia

dynamic equilibrium

acceleration due to gravity

static equilibrium

8. Force has:

both magnitude and direction

only magnitude

none of these

only direction

9. The turning effect of force is called:

none of these

moment of force

moment of force and torque

torque

10. perpendicular / base = :

sin θ

cosec θ

tan θ

cos θ

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

13N

10N

15N

12. A body is in unstable equilibrium after slight tilt if its center of gravity:

passes over the point of contact

is positioned at its bottom

remains on one side of the point of contact

remains above the point of contact

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

unstable equilibrium

none of these

stable equilibrium

neutral equilibrium

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

Newton metre

Newton per second

Newton

Newton second

15. The Center of gravity of a uniform triangular sheet is:

its center

the point of intersection of its medians

the mid-point on its axis

point of intersection of its diagonals

16. Torque depends upon:

the direction of the force and fulcrum

the mass and fulcrum

the magnitude of the velocity and fulcrum

the magnitude of the force and fulcrum

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

three

five

two

any number of

18. A paratrooper moving down with terminal velocity satisfies:

the first condition of equilibrium

Law of gravitation

the second condition of equilibrium

Newton’s second law of motion

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

remains at same height

is at its base

is at the lowest position

is at highest position

20. The following expression represents:

the second condition of equilibrium

the first condition of equilibrium

Newton’s first Law of motion

Newton’s second law of motion

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