Question

If machine ‘A’ delivers output equivalent to 600 watt and takes input power of 1000 watt,  machine ‘B’ delivers output 150 watts and takes input power of 200 watts, then which machine is more efficient?

Answer 1

Answer:

machine B is more efficient.

Explanation:

efficiency of machine A = 600/1000*100= 60%

efficiency of the machine B = 150/200*100= 75%

Answer 2

Answer:

Machine B is more efficient than machine A because machine B's efficiency is $75$ % and machine A's efficiency is $60$ %.

Explanation:

• The term used to measure the effectiveness of a machine to convert input power to output power is called efficiency.
• Efficiency is a dimensionless quantity.

The formula to calculate efficiency is:

$Efficiency=\frac{P_{o} }{P_{in}} *100$ %

where, $P_{o}$ is the output power.

            $P_{in}$ is the input power.

Step 1:

For machine A

$P_{o}=600$ $watt$

$P_{in}=1000$ $watt$

So, machine A's efficiency $=\frac{600 W}{1000W} *100$ %

                                             $=60$ %

Step 2:

For machine B

$P_{o}=150$ $watt$

$P_{in}=200$ $watt$

So, machine B's efficiency $=\frac{150 W}{200W} *100$ %

                                             $=75$ %

Hence, machine B is more efficient than machine A because machine B's efficiency is $75$ % and machine A's efficiency is $60$ %.