1 Efficiency of a machine is defined as the ratio of: A Work input to work output B Work output to work input C Load to effort D Distance moved by load to distance moved by effort
2 If the mass of an object is 10 kg on Earth, what is its mass on the Moon? A 10 kg B Less than 10 kg C More than 10 kg D Zero
3 A force that acts only when two surfaces are in contact is: A Gravitational force B Magnetic force C Friction D Electrostatic force
4 When a machine has an efficiency of 80%, it means: A 80% of input energy is wasted B 80% of input energy is converted into useful output C The machine produces more energy than it consumes D The machine has no friction
5 The force that acts on a body moving in a circular path and is directed towards the center is called: A Centrifugal force B Centripetal force C Frictional force D Gravitational force
6 The efficiency of a machine is defined as the ratio of: A Work input to work output B Work output to work input C Load to effort D Distance moved by load to distance moved by effort
7 The force that opposes the relative motion between two surfaces in contact is called: A Gravity B Friction C Magnetic force D Electrostatic force
8 If the mass of an object is 10 kg, what is its weight on Earth? (Take g = 9.8 m/s²) A 10 N B 9.8 N C 98 N D 0.98 N
10 The efficiency of a machine is defined as: A The ratio of output work to input work B The product of input work and output work C The sum of input work and output work D The difference between input work and output work
11 Which of the following is a contact force? A Magnetic force B Gravitational force C Friction D Electrostatic force
12 Which method is commonly used to reduce friction? A Increasing the weight of the object B Making surfaces rougher C Using lubricants D Increasing the contact area
13 The weight of an object is defined as: A The amount of matter in the object B The gravitational force acting on the object C The resistance of the object to motion D The force exerted by the object on a surface
14 Which of the following is a way to increase friction? A Applying oil B Using ball bearings C Making surfaces rough D Streamlining the shape
15 Which of the following is true about fundamental forces? A They are all contact forces B There are exactly four fundamental forces in nature C Friction is a fundamental force D Gravity is the strongest fundamental force
16 Which of the following is a fundamental force? A Friction B Electromagnetic force C Air resistance D Tension
17 The force of gravitation between two objects depends on: A Only the mass of the larger object B Only the distance between them C The masses of both objects and the distance between them D The volume of the objects
18 The weight of an object is: A The amount of matter in the object B The force with which the Earth attracts the object C The same as its mass D Zero at all places
19 Which of the following statements about mass and weight is correct? A Mass is a vector, weight is a scalar B Mass is measured in newtons, weight in kilograms C Mass is the amount of matter, weight is the force of gravity on the object D Mass changes with location, weight remains constant
20 The efficiency of a machine is usually: A Greater than 100% B Equal to 100% C Less than 100% D Equal to zero
21 Which fundamental force is responsible for holding the nucleons together in an atomic nucleus? A Strong nuclear force B Weak nuclear force C Electromagnetic force D Gravitational force
22 The force of attraction between two objects is directly proportional to: A The product of their masses B The distance between them C The square of the distance between them D The sum of their masses
23 Which fundamental force is the weakest? A Strong nuclear force B Electromagnetic force C Weak nuclear force D Gravitational force
24 Which force opposes the motion of an object moving through a fluid? A Gravitational force B Friction (drag) C Strong nuclear force D Electromagnetic force
25 A contact force that acts between surfaces in relative motion is: A Gravity B Friction C Magnetic force D Electrostatic force