A term brown out means it is an intentional or unintentional drop in voltage in an electrical power supply system.
Brown outs are long-term (hours-long) voltage sags caused by system overload.
Deviations from the regular sinusoidal wave, both on the utility side and on the customer side, result in poor power quality.
In single phase energy meter,
Current coil is made up from thick wire having few no. of turns.
Pressure coil is made up from thin wire having more no. of turns.
A wire pilot is generally economical for distances up to 5 or 10 miles, beyond which a carrier-current pilot usually becomes more economical.
Equivalent resistance of the circuit,
Req = (12||18) + 8
Req = 7.2 + 8
Req = 15.2 ohm
Source current = current through 8 ohm resistor, I = Vr/R8
I = 20/8
I = 2.5 A
Supply votage V = I*Req
V = 2.5*15.2
V = 38 V