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

1. According to the first condition for equilibrium:

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

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

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

13N

10N

15N

3. A body is in equilibrium when it has:

uniform speed and uniform acceleration

zero acceleration

uniform acceleration

uniform speed

4. The following expression represents:

Newton’s first Law of motion

the second condition of equilibrium

the first condition of equilibrium

Newton’s second law of motion

5. sin θ =:

base / hypotenuse

perpendicular / hypotenuse

base / hypotenuse

perpendicular / base

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

five

two

three

any number of

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

is at Lowest position

passes over the point of contact

remains above the point of contact

remains on one side of point of contact

8. Stability of a racing car is increased by:

increasing its height

lowering its centre of gravity

decreasing its width

raising its centre of gravity

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

unlike parallel forces

parallel forces

none of these

like parallel forces

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

stable equilibrium

neutral equilibrium

unstable equilibrium

None of these

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

point of intersection of its diagonals

its center

the point of intersection of its medians

the mid-point on its axis

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

two

three

five

four

13. perpendicular / base = :

cos θ

tan θ

cosec θ

sin θ

14. A paratrooper moving down with terminal velocity satisfies:

Newton’s second law of motion

the second condition of equilibrium

the first condition of equilibrium

Law of gravitation

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

is at highest position

is at the lowest position

is at its base

remains at same height

16. Force has:

only magnitude

both magnitude and direction

none of these

only direction

17. 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

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

Newton second

Newton

Newton metre

Newton per second

19. Graphical method is used for addition of:

three dimensional vector quantities

all of these

two dimensional vector quantities

one dimensional vector quantities

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

equal in magnitude

parallel, but opposite in direction

all of these

separated by a distance

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