What is SI unit of efficiency?

Answer 1

there is no unit. its usually a percent. so it would be something like joules/joules, which would be nothing.

Answer 2

Because efficiency is measured in a ratio.

Energy out of the machine divided by energy going into the machine equals efficiency.

You can get it as a percentage, but that's about it.

Answer 3

Efficiency is the ratio of output to input in a system. Since this invloves dividing one dimensional number by another with the same dimensions, the result is dimensionless. i.e. it has no units. The ratio is generally expressed as a percentage, as in "The generator has an efficiency of 33%", which indicates the output is approximately one third of the input.

Answer 4

"Effort" is not really a scientific term, (even though part of a lever is often called

the 'effort' arm).

The closest concept to 'effort' I can find in real Physics and SI units is "Force".

As you're certainly well aware, the SI unit of force is the Newton.

Answer 5

it has no unit as it is a ratio of two similar quantities

Answer 6

Efficiency is normally written as a percentage, and does not have an SI unit.percent. It has no units.

Answer 7

Efficiency is the ratio of output to input, and so is a dimensionless number, without units.

Answer 8

No. Efficiency is a unitless value.