Physics Practice: Simple Machines (Mock Test 4 - Expert)
1. In an experimental setup, a student uses a block and tackle system with 5 pulleys to lift a load. If the effort required is $25 \text{ N}$ to lift a load of $100 \text{ N}$, the actual Mechanical Advantage is:
2. Why does a worker use a long crowbar to lift a heavy stone instead of a short one?
3. A screw jack used to lift a car is a complex machine primarily combining which two simple machines?
4. Which of the following defines the "Velocity Ratio" ($VR$) of a machine?
5. If a machine has an efficiency of $75\%$, it means:
6. A pair of sugar tongs is a Class III lever. This means it acts as a:
7. To increase the efficiency of a pulley system, an expert technician should:
8. In a wheel and axle, if the radius of the wheel is $20 \text{ cm}$ and the radius of the axle is $4 \text{ cm}$, the Mechanical Advantage is:
9. Which of the following is true for an "Ideal Machine"?
10. Why is the blade of an axe made very thin near the edge?
11. A man uses a movable pulley to lift a bucket. The effort required is approximately ________ the weight of the bucket.
12. The Mechanical Advantage of an inclined plane increases when:
13. Which of the following is an example of a machine changing the point of application of force?
14. In a lemon squeezer, the lemon is placed in the middle. This makes it a:
15. The "moment of force" (torque) is mathematically defined as:
16. For a machine with $MA = 2$, an effort of $50 \text{ kgf}$ can lift a load of:
17. Which of these is the main disadvantage of a Class III lever?
18. The spiral path of a screw is actually an:
19. A machine that is $100\%$ efficient has no ________.
20. The force that we apply to use the handles of a pair of scissors is the:
