ICSE Class 10

General instructions: Answer all questions. Marks are shown in brackets [ ].

Objective

1. 1.
   What is a single movable pulley, and what is its mechanical advantage in the ideal case?

   1. A. A pulley whose axis remains fixed; its ideal mechanical advantage is 1.
   2. B. A pulley whose axis moves with the load; its ideal mechanical advantage is 2.
   3. C. A pulley that changes the direction of force; its ideal mechanical advantage is 1.
   4. D. A pulley whose axis moves with the load; its ideal mechanical advantage is 3.
   [1]
2. 2.
   For an ideal machine, what is the relationship between the ideal mechanical advantage (IMA) and the velocity ratio (V.R.)?

   1. A. IMA = V.R. / 2
   2. B. IMA = V.R.
   3. C. IMA = 2 × V.R.
   4. D. IMA = V.R. + 1
   [1]
3. 3.
   Which of the following is NOT one of the four primary ways in which machines are useful to us?

   1. A. Multiply force to lift or move heavy objects.
   2. B. Change the point of application of force for convenience.
   3. C. Generate energy to power themselves indefinitely.
   4. D. Change the direction of force to suit the task.
   [1]
4. 4.
   What is the mechanical advantage (M.A.) of a single movable pulley in the ideal case?

   1. A. 1
   2. B. 2
   3. C. 0.5
   4. D. 4
   [1]
5. 5.
   Which of the following best defines an inclined plane?

   1. A. A wheel and axle system
   2. B. A plank kept at an inclination to the ground acting as a force multiplier
   3. C. A lever with the fulcrum at the center
   4. D. A pulley system with multiple wheels
   [1]
6. 6.
   What is the velocity ratio of a single fixed pulley?

   1. A. 0.5
   2. B. 1
   3. C. 2
   4. D. The velocity ratio depends on the load
   [1]
7. 7.
   Which expression correctly shows the relationship between mechanical advantage (MA), velocity ratio (VR), and efficiency (η) for a simple machine?

   1. A. η = MA × VR
   2. B. η = MA / VR
   3. C. η = VR / MA
   4. D. η = MA + VR
   [1]
8. 8.
   What is the MA of the system of pulleys used in the below combination?

   1. A. 2 times the number of pulleys
   2. B. 2 / number of pulleys
   3. C. 2 ^ number of movable pulleys
   4. D. 2 + number of pulleys
   [1]
9. 9.
   Class II levers are designed to have

   1. A. M.A. = V.R.
   2. B. M.A. > V.R.
   3. C. M.A. > 1
   4. D. M.A. < 1
   [1]
10. 10.
    With reference to mechanical advantage, velocity ratio, and efficiency of a machine, which term remains unchanged for a machine of a given design?

    1. A. Mechanical advantage
    2. B. Velocity ratio
    3. C. Efficiency
    4. D. Power output
    [1]
11. 11.
    Assertion (A): Scissors are an example of a first-class lever. Reason (R): In a pair of scissors, the fulcrum is between the handles (effort) and the blades (load). Which of the following is correct?

    1. A. Both A and R are true, and R is the correct explanation of A
    2. B. Both A and R are true, but R is not the correct explanation of A
    3. C. A is true, but R is false
    4. D. A is false, but R is true
    [1]
12. 12.
    A woman lifts a load of 6 kg using a lever. The force applied by the woman is 70 N. Calculate the mechanical advantage. (Take g = 10 m s⁻²)

    1. A. 0.857
    2. B. 1.17
    3. C. 8.57
    4. D. -0.857
    [1]
13. 13.
    In the given diagram of the forearm (img-24.jpeg), which positions correspond to the Load, Effort, and Fulcrum?

    1. A. Fulcrum at elbow, Effort at biceps, Load at hand
    2. B. Fulcrum at hand, Effort at elbow, Load at biceps
    3. C. Fulcrum at biceps, Effort at elbow, Load at hand
    4. D. Fulcrum at hand, Effort at biceps, Load at elbow
    [1]
14. 14.
    How does the actual mechanical advantage (AMA) differ from the ideal mechanical advantage (IMA) in a machine?

    1. A. AMA equals IMA plus friction losses.
    2. B. AMA is always greater than IMA due to efficiency.
    3. C. AMA is less than IMA due to friction and movable parts.
    4. D. AMA and IMA are always equal in real machines.
    [1]
15. 15.
    Why is the efficiency of a single movable pulley not 100%? Select the two primary reasons from the options below.

    1. A. Friction in the pulley bearings and the weight of the movable pulley itself.
    2. B. The pulley is not perfectly circular and the rope slips off easily.
    3. C. Air resistance acting on the pulley and the rope being too thin.
    4. D. The effort applied is not constant and the load is unevenly distributed.
    [1]
16. 16.
    Decrease in mechanical advantage would the efficiency.

    1. A. increase
    2. B. not affect
    3. C. decrease
    4. D. none of these
    [1]
17. 17.
    A worker pushes a box weighing 1500 N up a ramp 6.00 m long onto a platform 1.50 m above the ground. What is the effort applied by the worker?

    1. A. 250 N
    2. B. 375 N
    3. C. 600 N
    4. D. 1500 N
    [1]
18. 18.
    Which class of levers always has a mechanical advantage greater than one, and how can its mechanical advantage be increased?

    1. A. Class I lever; increase the effort arm
    2. B. Class II lever; decrease the load arm
    3. C. Class III lever; increase the load arm
    4. D. Class II lever; increase the load arm
    [1]
19. 19.
    Why does a class III lever always have a mechanical advantage less than one? (Refer to img-26.jpeg for the diagram.)

    1. A. The effort arm is longer than the load arm
    2. B. The effort is applied between the fulcrum and the load
    3. C. The load arm is shorter than the effort arm
    4. D. The fulcrum is positioned at the load
    [1]
20. 20.
    Derive the relationship that connects mechanical advantage (M.A.), velocity ratio (V.R.), and efficiency of a machine. Which of the following correctly expresses this relationship?

    1. A. Efficiency = (M.A. × V.R.) × 100%
    2. B. Efficiency = (M.A. / V.R.) × 100%
    3. C. Efficiency = (V.R. / M.A.) × 100%
    4. D. Efficiency = M.A. + V.R. × 100%
    [1]