Question

R1=5ohms R2=10 ohms R3 =20ohms calculate the total resistance of circuit​

Answer 1

I(Total) = 30 Amps

IR1 = 6 Amps R1 = 20 Ohms

IR2 = 12 Amps R2 = 10 Ohms

IR3 = ? Amps R3 = ? Ohms

IT = I1 + I2 + I3

IT - I1 - I2 = I3

I3 = 30 Amps - 6 Amps - 12 Amps = 12 Amps

VT = R1 x IR1 = R2 x IR2 = R3 x IR3

VT = 10 Ohms x 12 Amps = 120 Volts

R3 = VT / IR3

R3 = 120 Volts / 12 Amps = 10 Ohms

VT = RT x IT

RT = VT / IT

RT = 120 Volts / 30 Amps = 4 Ohms

1 / RT = 1 / R1 + 1 / R2 + 1 / R3

RT = 1 / (1 / R1 + 1 / R2 + 1 / R3)

RT = 1 / (1 / 20 + 1 / 10 + 1 / 10) Ohms

RT = 1 / (1 / 20 + 2 / 20 + 2 / 20) Ohms

RT = 1 / (5 / 20 ) Ohms

RT = 20 / 5 Ohms

RT = 4 Ohms