Question 1

A wedge is used to split a log. The wedge has a length of 20 cm and a thickness of 4 cm at its base. What is the mechanical advantage of this wedge? (Assume the wedge is ideal.)

Accepted Answer

The mechanical advantage of a wedge is defined as the ratio of its length to its thickness: MA = Length ÷ Thickness = 20 cm ÷ 4 cm = 5. This is a direct application of the NCERT Class 10 definition of mechanical advantage for wedges, where the longer and thinner the wedge, the greater its mechanical advantage.

Question 2

A simple machine has a mechanical advantage of 4. If an effort of 50 N is applied to lift a load, what is the load being lifted? (Assume the machine is ideal with no friction losses.)

Accepted Answer

Mechanical Advantage (MA) is defined as the ratio of Load to Effort. For an ideal machine, MA = Load ÷ Effort. Therefore, Load = MA × Effort = 4 × 50 N = 200 N. This is a direct application of the NCERT Class 10 definition of mechanical advantage for simple machines.

Question 3

A movable pulley system is used to lift a load of 1200 N. If the effort applied is 400 N, what is the mechanical advantage of this pulley system?

Accepted Answer

Mechanical Advantage (MA) is defined as the ratio of Load to Effort. MA = Load ÷ Effort = 1200 N ÷ 400 N = 3. A movable pulley typically provides an MA of 2 or more because the load is supported by multiple segments of the rope. In this case, the MA of 3 indicates a system with three supporting rope segments. Therefore, the answer is B.

Question 4

An inclined plane of length 5 m is used to raise a load of 1000 N to a height of 3 m. Assuming no friction, what is the effort required to push the load up the plane?

Accepted Answer

For an ideal inclined plane, Work Input = Work Output. Effort × Length of plane = Load × Height. Therefore, Effort = (Load × Height) ÷ Length = (1000 N × 3 m) ÷ 5 m = 3000 ÷ 5 = 600 N. This applies the NCERT Class 10 principle of conservation of energy and work for inclined planes.

Question 5

A movable pulley system uses 4 supporting ropes to lift a load. If the load is 800 N, what is the minimum effort required to lift it? (Assume the pulley system is ideal with no friction.)

Accepted Answer

In a movable pulley system, the mechanical advantage equals the number of supporting ropes. With 4 supporting ropes, MA = 4. Therefore, Effort = Load ÷ MA = 800 N ÷ 4 = 200 N. This directly applies the NCERT Class 10 principle that each supporting rope shares the load equally in an ideal pulley system.

Question 6

A lever of length 2 m has its fulcrum at 0.5 m from one end. If a load of 300 N is placed at the end nearest the fulcrum, what effort is needed at the other end to balance the lever? (Assume the lever is ideal.)

Accepted Answer

For a lever in equilibrium, the principle of moments applies: Load × Load Arm = Effort × Effort Arm. Load arm = 0.5 m, Effort arm = 2 - 0.5 = 1.5 m. Therefore, Effort = (Load × Load Arm) ÷ Effort Arm = (300 × 0.5) ÷ 1.5 = 150 ÷ 1.5 = 100 N. This directly applies the NCERT Class 10 principle of moments for levers.

Question 7

A movable pulley system is used to lift a load of 1200 N. If the effort applied is 400 N and the length of the effort rope pulled is 3 m, what is the mechanical advantage and distance moved by the load respectively?

Accepted Answer

Mechanical Advantage (MA) of a movable pulley system is defined as the ratio of Load to Effort. Here, MA = Load ÷ Effort = 1200 N ÷ 400 N = 3. For an ideal movable pulley with MA = 3, the distance moved by the load is inversely proportional to the effort distance. Using the principle of work conservation (Effort × Effort distance = Load × Load distance), we get: 400 × 3 = 1200 × Load distance, which gives Load distance = 1 m. Therefore, MA = 3 and distance moved by load = 1 m. The correct answer is B.

CDS Simple Machines

Simple Machines— Rules & Concept

Key Points to Remember

Exam-Specific Tips

Simple Machines — Practice Questions

60-Second Revision — Simple Machines