Physics Practice: Machines (Mock Test 5 - Ultimate Comprehensive)
1. Which of the following statements is TRUE for all real machines?
2. A block and tackle system has 5 pulleys. If the efficiency is $80\%$, the Mechanical Advantage is:
3. A pair of pliers is a Class I lever. It acts as a ________ multiplier because the ________ arm is longer.
4. The $V.R.$ of a single fixed pulley is 1, while for a single movable pulley it is 2. The reason for this difference is:
5. Which lever class is used when the main objective is to gain speed, despite needing a larger effort?
6. A machine has a $V.R. = 10$. If the effort moves $5 \text{ m}$, the load moves:
7. A wheelbarrow is a Class II lever. If the center of gravity of the load is $20 \text{ cm}$ from the wheel axle and the handles are $100 \text{ cm}$ from the axle, the $M.A.$ is:
8. In a block and tackle system with an odd number of pulleys, say 3, how are they distributed?
9. The efficiency of a machine can be improved by:
10. If $W_i$ is work input, $W_o$ is work output, and $W_l$ is work lost, which is correct?
11. A human arm lifting a weight is a Class III lever. Where is the effort applied?
12. An ideal machine has $M.A. = 4$. What effort is needed to lift a $200 \text{ N}$ load?
13. In a single fixed pulley, the tension $T$ in the string is equal to:
14. A fishing rod allows a fisherman to move a fish through a large distance by moving his hands a small distance. This means:
15. A block and tackle system has 4 pulleys. If the rope is pulled with a velocity of $20 \text{ m/s}$, the load rises with a velocity of:
16. Mechanical Advantage has ________ units.
17. For a Class II lever, the effort is always ________ than the load.
18. The $V.R.$ of a machine is 5 and its efficiency is $60\%$. The effort needed to lift a load of $150 \text{ N}$ is:
19. In a block and tackle system, $M.A.$ can be equal to $V.R.$ only if:
