Efficiency of a machine equals:
AM.A. / V.R. * 100 percent
BM.A. * V.R. in standard practice
CM.A. + V.R.
DLoad / effort
Answer & Solution
Correct answer: A. M.A. / V.R. * 100 percent
1. Efficiency compares useful output to total input.
2. In a machine context, eta = (M.A. / V.R.) * 100 percent.
3. An ideal machine has M.A. = V.R., so eta = 100 percent.
4. Real machines have eta less than 100 percent.
_Source: Selina Concise Physics ICSE Class 10, Ch 3 'Machines' (aplustopper.com extract)_
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