## Physics (Objective) (Pages :44) <<< Back

• 61 Propulsion of rocket is explained by which law of motion?

Ans : Newton’s Third law of motion
• 62 Swimming is explained by which law of motion?

Ans : Newton’s Third law of motion
• 63 Flying of Birds is explained by which law of motion?

Ans : Newton’s Third law of motion
• 64 A property of a body which is unable to change its state by itself in the absense of external force called?

Ans : Inertia
• 65 The Law of inertia was discovered by?

Ans : Galileo
• 66 Which are the three types of inertia?

Ans : Inertia of Rest; Inertia of Motion and Inertia of Direction
• 67 An athlete runs some distance before taking a long jump is example of?

Ans : Inertia of motion
• 68 As the train starts moving, a man sitting inside leans backward is an example of?

Ans : Inertia of rest
• 69 Rotating wheel of an automobile throw out mud tangentially outward is an example of?

Ans : Inertia of direction
• 70 If a rotating body spins on its axis, its motion is called?

Ans : Spin motion or rotation motion
• 71 When an object travels around another object it is known as?

Ans : Revolution
• 72 The motion of an object in a vertical plane under the influence of gravitational force is known as?

Ans : Projectile motion
• 73 Projectile path is known as?

Ans : Trajectory
• 74 A projectile reaches maximum range, when angle of projection is at?

Ans : 450
• 75 The path of the projectile is always a?

Ans : Parabola
• 76 An influence that changes the state of rest in a straight line of a body is called?

Ans : Force F= ma [m = mass; a = acceleration]
• 77 Unit of Force is?

Ans : Newton or Kg m/s2
• 78 CGS unit of Force is -?

Ans : Dyne
• 79 Strongest force in the universe is?

Ans : Nuclear force
• 80 Weakest force in the universe, ?

Ans : Gravitational Force
• 81 Force acting for a short time?

Ans : Impulsive force
• 82 Force which acts on a body moving in a circular path and it is directed towards centre is called?

Ans : Centripetal force
• 83 The force required by a Vehicle moving round a curved road is?

Ans : Centripetal force
• 84 Force that acts on a body moving in a circular path and is directed away from the centre is called?

Ans : Centrifugal force
• 85 The force that helps to separate cream from milk is?

Ans : Centrifugal force
• 86 Capability of rotating objects around a fixed axis is called?

Ans : Torque
• 87 Force that resists the movement of one surface over another is called?

Ans : Frictional Force
• 88 The substances which reduce the frictional force between moving surfaces?

Ans : Lubricants eg : Grease; Oil; Graphite
• 89 Force acts in a direction opposite to the direction of motion is?

Ans : Static friction
• 90 Force occurs when two objects are moving relative to each other or rub together is?

Ans : Kinetic friction

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