A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistances, which may be used separately, in series, or in parallel

Q.13:- A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistances, which may be used separately, in series, or in parallel. What are the currents in the three cases?

 

Answer:-

Supply voltage, V = 220 V
Here Resistance of one coil, R =24 Ω
(i) Coils are used separately
According to Ohm’s law, V=I1R1
 Iis the current flowing through the coil
I1=V/R1=220/24=9.166A
∴ current flow through the coil when used separately is 9.16 A.
 (ii) Coils are connected in series
R2=24 Ω+24 Ω=48 Ω
According to Ohm’s law
I2=V/R2=220/48=4.58A
the current flowing through the series circuit is 4.58A
(iii) Coils are connected in parallel
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According to Ohm’s law
I3=V/R3=220/12=18.33A
the current flowing through the parallel circuit is 18.33A