An electric heater which is connected to 220 V supply line has two resistance coils A and B of 24 Ω resistance each. These coils can be used separately (one at a time), in series or in parallel. Calculate the current drawn when:
(a) only one coil A is used.
(b) coils A and B are used in series
(c) coils A and B are used in parallel.
(a) When only one coil, A is used
V= IR
220= 24I
I=9.2
(b) When coils A and B are used in series.
Total resistance R= RA +RB = 24+24 = 48ohms
I = V/R = 220/48
=4.58amps
(c) When coils A and B are used in parallel.
R=12ohms
I = V/R = 220/12
=18.33amps
22