1 A body is in dynamic equilibrium when it: A Is at rest B Moves with uniform velocity C Moves with changing velocity D Has zero mass
2 The first condition of equilibrium is that the net force acting on a body must be: A Zero B Maximum C Constant D Variable
3 When a body moves in a direction opposite to the applied force, the work done by the force is: A Positive B Negative C Zero D Infinite
4 Which of the following is a social impact of using fossil fuels? A Reduced air pollution B Health problems due to pollution C Increased crop yield D Clean water supply
5 The efficiency of a machine is 80%. If it receives 500 J of energy, how much useful work is done? A 100 J B 400 J C 500 J D 625 J
6 Which condition is necessary for a body to be in equilibrium? A Net force is zero B Net torque is zero C Both net force and net torque are zero D Net force is maximum
7 A body is in neutral equilibrium if after a small displacement it: A Returns to its original position B Moves away from its original position C Stays in its new position D Falls down
9 When a force of 10 N acts on a body and moves it 2 m in the direction of the force, the work done is: A 5 J B 10 J C 20 J D 40 J
10 Racing cars are designed with a low centre of gravity mainly to: A Increase their speed B Improve their stability C Reduce their mass D Increase their fuel efficiency
11 Which of the following is a state of equilibrium? A A ball rolling down a slope B A book lying on a table C A car taking a turn D A stone falling freely
12 A force of 50 N makes an angle of 30° with the horizontal. Its vertical component is: A 25 N B 43.3 N C 50 N D 100 N
13 The perpendicular distance from the pivot to the line of action of a force is called: A Moment arm B Force arm C Couple arm D Resultant
15 Which of the following is an example of a couple? A Two equal and opposite forces acting along the same line B Two equal and opposite forces acting along different parallel lines C Two unequal forces acting in the same direction D A single force acting at a point
16 The stability of a body can be increased by: A Raising its centre of gravity B Narrowing its base C Lowering its centre of gravity D Making its line of action fall outside the base
17 A body is said to be in neutral equilibrium if, when slightly displaced, its centre of gravity: A Rises B Falls C Remains at the same height D Moves horizontally only
18 The centre of gravity of a triangular lamina is located at the intersection of its: A Sides B Altitudes C Medians D Angles
19 A racing car is designed with a low centre of gravity and a wide base to: A Increase its weight B Decrease its speed C Improve its stability D Increase its fuel consumption
20 According to the law of conservation of energy, energy can: A Be created but not destroyed B Be destroyed but not created C Neither be created nor destroyed D Be created and destroyed
21 Which energy source is derived from the heat of the Earth? A Solar energy B Wind energy C Geothermal energy D Tidal energy
22 A stone tied to a string and whirled in a circle moves along a tangent when the string breaks because: A Centripetal force keeps acting B The stone has no inertia C The centripetal force is removed D Gravity pulls it along the tangent
23 Why is 100% efficiency not possible in a machine? A Because input energy is always less than output energy B Because some energy is wasted due to friction and other losses C Because output power is always greater than input power D Because machines create extra energy
24 According to the principle of moments, for a body in equilibrium: A Clockwise moments are greater than anticlockwise moments B Anticlockwise moments are greater than clockwise moments C Clockwise moments equal anticlockwise moments D Sum of all moments is maximum
25 The centre of gravity of an irregular lamina can be found by: A Measuring its mass B Suspending it from different points C Heating it D Cutting it into pieces