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

1. 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

2. Bunsen burner is made stable by:

increasing its mass

decreasing its base area

increasing its base area

increasing its length

3. States of equilibrium are:

two

five

four

three

4. 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

5. perpendicular / base = :

cos θ

tan θ

cosec θ

sin θ

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

Newton metre

Newton per second

Newton

Newton second

7. States of equilibrium are:

three

five

two

four

8. 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

9. 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

neutral equilibrium

none of these

10. Graphical method is used for addition of:

two dimensional vector quantities

three dimensional vector quantities

one dimensional vector quantities

all of these

11. According to the first condition for equilibrium:

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

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

sum of all torques acting on a body is constant

sum of all torques acting on a body is zero

12. The following expression represents:

the first condition of equilibrium

Newton’s first Law of motion

Newton’s second law of motion

the second condition of equilibrium

13. Torque depends upon:

the magnitude of the force and fulcrum

the mass and fulcrum

the magnitude of the velocity and fulcrum

the direction of the force and fulcrum

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

stable equilibrium

None of these

unstable equilibrium

neutral equilibrium

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

dynamic equilibrium

acceleration due to gravity

static equilibrium

inertia

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

parallel, but opposite in direction

equal in magnitude

separated by a distance

all of these

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

torque

equilibrium

a couple

unstable equilibrium

18. 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

passes over the point of contact

remains on one side of the point of contact

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

15N

13N

10N

20. Stability of a racing car is increased by:

increasing its height

raising its centre of gravity

lowering its centre of gravity

decreasing its width

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