How to calculate the consumed electric energy according to the revolutions and time of the electric energy meter?

How to calculate the consumed electric energy according to the revolutions and time of the electric energy meter?

W=n/N
P=W/t=n/Nt
N is the actual revolution
N is the number of revolutions on the meter

Revolution of electric energy meter
XX connects a 100W lamp to the circuit separately, and observes that the electric energy meter turns five revolutions in one minute. Then, let the color TV stand alone in the circuit and be in standby mode, and the electric energy meter turns two revolutions in five minutes. From this, we can judge that the standby power of the color TV is?
Take this problem as an example, physics experts tell me about it. Thank you~~
You can be more specific on the fourth floor, thank you

The power is 8W
Divide the power of appliance a by the speed of appliance a per minute
be equal to
Divide the power of electric appliance B by the speed of electric appliance B per minute
Because the rotation speed of the electric energy meter is proportional to the power of the electric appliance

What does the parameter "10 (20) a" on the energy meter mean?

10A is the normal working current, 20A is the maximum current that can pass in a short time

What does the 5 (20) a on the meter mean
If the circuit current is 15a, can a 5 (20) a meter be used

5 (20) a on the watt hour meter indicates the rated current of 5A and the maximum working current of 20a
If the circuit current is 15a, a 5 (20) a meter can be used