Live Education Quiz

1

What is meant by the resultant force?

A Force that stops motion B Single force having same effect as multiple forces C Force due to gravity only D Force applied by an object

2

If all forces acting on a body cancel each other, the resultant force is:

A Maximum B Minimum C Zero D Infinite

3

Newton’s Second Law of Motion relates force with:

A Velocity B Momentum C Acceleration D Distance

4

The mathematical form of Newton’s Second Law is:

A F = mv B F = ma C F = m/a D F = a/m

5

Unit of force in SI system is:

A Dyne B Joule C Newton D Watt

6

If mass of a body is doubled and force remains same, acceleration will:

A Double B Become half C Remain same D Become zero

7

Newton’s Third Law of Motion states that:

A Force equals mass times acceleration B Every action has an equal and opposite reaction C Body remains at rest or in motion D Momentum is conserved

8

Action and reaction forces act on:

A Same body B Different bodies C Same direction D Same surface

9

Which of the following is an example of action-reaction pair?

A Weight and mass B Push on wall and wall pushing back C Friction and gravity D Speed and velocity

10

Why does a gun recoil when a bullet is fired?

A Due to gravity B Due to friction C Due to Newton’s Third Law D Due to inertia

11

Which law explains motion of rockets?

A First law B Second law C Third law D Law of gravitation

12

Momentum of a body depends on:

A Mass only B Velocity only C Mass and velocity D Force and mass

13

Formula of momentum is:

A p = mv B p = ma C p = m/v D p = v/m

14

SI unit of momentum is:

A kg m s⁻¹ B kg m s⁻² C N s⁻¹ D J s

15

Impulse is equal to:

A Force × distance B Force × time C Mass × acceleration D Momentum ÷ time

16

Impulse is equal to change in:

A Force B Velocity C Momentum D Mass

17

Unit of impulse is:

A Newton B Newton second C Joule D Watt

18

Which of the following increases impulse?

A Decreasing time B Increasing time C Decreasing force D Decreasing momentum

19

Why are airbags used in cars?

A To increase speed B To decrease force by increasing time C To reduce mass D To stop motion instantly

20

Principle of conservation of momentum states that:

A Momentum always increases B Momentum is lost in collisions C Total momentum remains constant D Momentum depends on force

21

A body is in equilibrium when its:

A acceleration is zero. B speed is zero. C velocity is non-uniform. D displacement is zero.

22

A couple is formed by:

A two forces perpendicular to each other. B two equal and opposite forces not in the same line. C two equal and opposite forces in the same line. D two unequal forces.

23

The vertical or perpendicular component of a force F making an angle θ with the horizontal x-axis is given by:

A F cos(θ) B F tan(θ) C F sin(θ) D F cot(θ)

24

The turning effect of a force is called:

A Momentum B Pressure C Work D Torque

25

The centre of gravity of an irregularly shaped thin lamina can be found using a:

A Plumb line B Screw gauge C Vernier callipers D Metre rule

Chapter 4: Dynamics – II