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

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

neutral equilibrium

unstable equilibrium

stable equilibrium

none of these

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

passes over the point of contact

remains above the point of contact

is at Lowest position

remains on one side of point of contact

3. sin θ =:

base / hypotenuse

perpendicular / base

base / hypotenuse

perpendicular / hypotenuse

4. perpendicular / base = :

sin θ

cosec θ

tan θ

cos θ

5. Graphical method is used for addition of:

one dimensional vector quantities

all of these

three dimensional vector quantities

two dimensional vector quantities

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

unstable equilibrium

None of these

neutral equilibrium

stable equilibrium

7. 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

8. Bunsen burner is made stable by:

decreasing its base area

increasing its length

increasing its mass

increasing its base area

9. States of equilibrium are:

four

five

three

two

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

a couple

torque

equilibrium

unstable equilibrium

11. A body is in equilibrium when it has:

zero acceleration

uniform acceleration

uniform speed

uniform speed and uniform acceleration

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

equal in magnitude

parallel, but opposite in direction

separated by a distance

all of these

13. The turning effect of force is called:

torque

moment of force

moment of force and torque

none of these

14. Stability of a racing car is increased by:

decreasing its width

increasing its height

lowering its centre of gravity

raising its centre of gravity

15. 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

16. The forces that act along opposite directions are called:

unlike parallel forces

parallel forces

like parallel forces

none of these

17. Force has:

only direction

none of these

only magnitude

both magnitude and direction

18. The following expression represents:

Newton’s first Law of motion

the first condition of equilibrium

the second condition of equilibrium

Newton’s second law of motion

19. They form a couple.

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

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

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

remains above the point of contact

remains on one side of the point of contact

is positioned at its bottom

passes over the point of contact

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