📝 Exercise on Simple Machines
📌 Objective Questions (Choose the correct answer)
1. See-saw is an example of:
- a. Class I lever
- b. Class II lever
- c. Class III lever
- d. All of the above
✅ Correct Answer: a. Class I lever
2. Knife is an example of:
- a. An inclined plane
- b. A screw
- c. A wedge
- d. Wheel and axle
✅ Correct Answer: c. A wedge
3. Which of the following is the best way for items to be hoisted high in the cargo lift system?
- a. Using a pulley
- b. Using an inclined plane
- c. Using a staircase
- d. None of the above
✅ Correct Answer: a. Using a pulley
4. At equilibrium, Load × ? = Effort × ?
- a. Effort arm; Load arm
- b. Load arm; Effort arm
- c. MA; Load arm
- d. None of the above
✅ Correct Answer: b. Load arm; Effort arm
5. ______ has no unit.
- a. Effort arm
- b. Mechanical advantage
- c. Load arm
- d. Load
✅ Correct Answer: b. Mechanical advantage
✍️ Fill in the blanks
1. ______ is the point about which a lever can rotate.
✅ Answer: Fulcrum
2. The unit of effort and load is ______.
✅ Answer: newton (N)
3. In Class II lever, ______ is in between the fulcrum and ______.
✅ Answer: Load is in between the fulcrum and effort
4. A ______ is an inclined plane wrapped spirally around a cylinder.
✅ Answer: Screw
5. If mechanical advantage is equal to 1, then effort = ______.
✅ Answer: Load
✔️ True or False
1. In Class II levers, more effort is required to overcome a large force.
❌ False (Less effort is required in Class II levers)
2. A screw converts rotational motion to linear motion.
✅ True
3. A wedge is used to break things apart.
✅ True
4. A broom is an example of Class I lever.
❌ False (A broom is a Class III lever)
5. Spiral staircase is an example of inclined plane.
✅ True
🔗 Match the following
Match the following pairs:
1. A simple machine used to change the direction of effort in a convenient direction 2. A lever in which less effort is applied to overcome heavier loads 3. A pulley that moves with the load 4. A lever where more effort is required to overcome a load 5. The force that is applied to overcome the load
✅ Answers:
1 → c. Single fixed pulley
2 → a. Class II lever
3 → b. Single movable pulley
4 → e. Class III lever
5 → d. Effort
