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

1. According to the first condition for equilibrium:

sum of all torques acting on a body is zero

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

sum of all torques acting on a body is constant

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

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

stable equilibrium

unstable equilibrium

none of these

neutral equilibrium

3. States of equilibrium are:

three

four

five

two

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

15N

13N

10N

5. The Center of gravity of uniform square or a rectangular sheet is the:

the point of intersection of its medians

its center

the mid-point on its axis

point of intersection of its diagonals

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

parallel, but opposite in direction

separated by a distance

equal in magnitude

all of these

7. A body is in stable equilibrium after slight tilt if its center of gravity:

remains above the point of contact

is at Lowest position

remains on one side of point of contact

passes over the point of contact

8. Torque depends upon:

the magnitude of the force and fulcrum

the magnitude of the velocity and fulcrum

the mass and fulcrum

the direction of the force and fulcrum

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

is positioned at its bottom

remains above the point of contact

remains on one side of the point of contact

passes over the point of contact

10. A paratrooper moving down with terminal velocity satisfies:

Law of gravitation

Newton’s second law of motion

the first condition of equilibrium

the second condition of equilibrium

11. perpendicular / base = :

tan θ

sin θ

cosec θ

cos θ

12. A right rope walker carries a long pole to:

keep his centre of gravity in fixed position

increase his weight

lower his centre of gravity

raise his centre of gravity

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

stable equilibrium

unstable equilibrium

None of these

neutral equilibrium

14. The following expression represents:

the second condition of equilibrium

Newton’s second law of motion

Newton’s first Law of motion

the first condition of equilibrium

15. States of equilibrium are:

four

two

five

three

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

two

five

three

four

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

five

two

three

any number of

18. Stability of a racing car is increased by:

raising its centre of gravity

lowering its centre of gravity

decreasing its width

increasing its height

19. According to the second condition for equilibrium:

sum of all torques acting on a body is constant

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 the all, forces acting on a body must be constant

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

torque

equilibrium

a couple

unstable equilibrium

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