Physics Practice: Machines (Mock Test 2 - Intermediate)
1. A crowbar of length $120 \text{ cm}$ has its fulcrum situated at a distance of $20 \text{ cm}$ from the load. The Mechanical Advantage (M.A.) is:
2. In a single movable pulley, if the load is $100 \text{ N}$, the effort required in an ideal case is:
3. Which part of the human body acts as a Class III lever while lifting a weight on the palm?
4. For a machine to act as a force multiplier, which condition must be true?
5. A block and tackle system has $5$ pulleys. If an effort of $1000 \text{ N}$ is needed to lift a load of $4000 \text{ N}$, the efficiency is:
6. A nutcracker is a lever of which class?
7. In a lever of Class III, the effort arm is ________ than the load arm.
8. A single fixed pulley has an efficiency of $90\%$. If a load of $90 \text{ N}$ is lifted, the effort required is:
9. Which of the following is NOT a simple machine?
10. The M.A. of a single movable pulley system is $2$. If the load moves up by $1 \text{ m}$, the point of application of effort moves by:
11. A seesaw is a Class I lever. If two children of equal weight sit at equal distances from the fulcrum, the M.A. is:
12. Why can the efficiency of a machine never be $100\%$ in practice?
13. In a pulley system, the tension $T$ in the string is assumed to be ________ throughout the string.
14. To increase the M.A. of a Class II lever, we should:
15. A block and tackle system has $4$ pulleys. The V.R. is:
16. The mechanical advantage of a machine is $5$ and its velocity ratio is $10$. Its efficiency is:
17. A fishing rod is an example of a Class III lever because:
18. For a machine used as a speed multiplier, the velocity ratio is:
19. If the M.A. of a lever is $1$, it is used to:
20. The work input of a machine is $500 \text{ J}$ and work output is $400 \text{ J}$. The energy wasted is: