Question

An electric heater which is connected to a 220 V supply line has two resistance coils. A and B of $24\Omega$ resistance each. these coils can be used separately (one at a time), in series or in parallel. calculate the current drawn when:

1. Only one coil A is used
2. coils A and B are used in series
   

Answer 1

➡When Series

R = R1 + R2

R = 24 + 24

R = 48 ohm

V = R × I ( Ohm's law )

I = V / R

I = 220 / 48 = 4.583333333 Amp

➡When parallel

1 / R = 1 / 24 + 1 / 24

1 / R = 2 / 24

1 / R = 1 / 12

R = 12 ohm

I = V / R

I = 220 / 12

I = 18.33333333 Amp