InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Give two reasons, why the efficiency of a single movable pulley system is not 100%? |
|
Answer» (i) Due to friction in the movable parts of the pulley. (ii) Due to weight of the movable pulley. |
|
| 2. |
State two reasons, why the efficiency of a pulley system is not 100 per cent? |
|
Answer» The two reasons are: (i) Some effort is used (or wasted) in overcoming friction between the string and the grooves of the pulleys. (ii) Some effort is used up (wasted) in lifting up the movable block alongwith the load. On account of the above two reasons, effort applied is always more than the load lifted up and so the M.A. is always less then 1. Hence efficiency is always less than 100%. |
|
| 3. |
When we want to use a machine as a force multiplier, which class of lever should we preferably use? Give a simple diagram of such a lever. |
|
Answer» Though we can use either levers of class I or class II, for multiplying force, we should preferably use a lever of class II. This is because the mechanical advantage of levers of class II, is always greater than one. A simple diagram of a lever of class II is shown alongside. The wheel barrow, the bottle opener and the mango cutter are some of the practical forms of lever of class II. |
|