Physics
Efficiency is defined as the ratio of work done by a machine to the work done on a machine. Every machine that we use in our lives has an efficiency that allows us to assess the performance of the machine. Percentage efficiency of some machines is given in the table.
| Machine | Efficiency (%) |
|---|---|
| Heat engine | 40 |
| Solar panels | 15 |
| Steam turbine | 35 |
| Electric generator | 90 |
| Carnot engine | 50 |
Now, answer the following questions.
(a) Which machine has the highest efficiency? What does it mean?
(b) Which machine has the lowest efficiency? What does it mean?
(c) Are these simple machines or complex machines?
(d) What is the formula to calculate efficiency of a machine?
(f) Are any of these machines ideal? If no, why?
(g) Using the Internet, find out where these machines are used.
Related Questions
Mechanical advantage is the ratio of load lifted by a machine to the effort applied. Every simple machine has a mechanical advantage. The effort and load of some machines are given. Calculate the MA of each machine.
Machine Effort (N) Load (N) Mechanical Advantage A 20 60 B 140 70 C 10 100 D 5 25 E 15 45 F 120 60 Draw a line graph of the given data. Take effort on X-axis and load on Y-axis.
Wedges are made up of two inclined planes. How will you find MA of a wedge?
If you want to increase the MA of a machine, what should be increased or decreased?
Is it possible to balance the load and effort by changing the position of fulcrum?