Quote:
Originally Posted by SADIA SHAFIQ
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Sadia the link you have provided is about an Ideal machine where there is no power loss which is not possible in real.
Here is an excerpt for you.
Mechanical efficiency measures the effectiveness of a machine in transforming the energy and power that is input to the device into an output force and movement. Efficiency is measured as a ratio of the measured performance to the performance of an ideal machine:
Efficiency = Measured Performance / Ideal Performance
Because the power transmission system or mechanism does not generate power, its ideal performance occurs when the output power equals the input power, that is when there are no losses.
Real devices dissipate power through friction, part deformation and wear.
The ideal transmission or mechanism has an efficiency of 100%,
because there is no power loss. Real devices will have efficiencies less than 100% because rigid and frictionless systems do not exist. The power losses in a transmission or mechanism are eventually dissipated as heat.
Source:
http://en.wikipedia.org/wiki/Mechanical_efficiency
Quote:
Originally Posted by SADIA SHAFIQ
you are right dear 
please tell me about RAM and ROM .because I am oblivious of computer terms . |
ROM is for Read-Only Memory. This is something which once burnt cant be altered later on and they can be read only. You must have read the name CD-ROM . That is a compact disc to which data has been burnt and that can be read only. Same goes for different computer chips responsible for operation of different machines.
Now RAM is random access memory. When you click a program the cpu loads it from hard disk to ram and from RAM it is being run. You must have experienced that that less ram and many programs open result in sluggish performance of computer and vice versa.
For more study follow these links.
http://en.wikipedia.org/wiki/Random-access_memory
http://en.wikipedia.org/wiki/Read-only_memory