An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected in parallel to a 220 V source

Q. An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances, and what is the current through it?

 

Answer:-

Resistance of electric lamp (R1) = 100 Ω
Resistance of toaster (R2) = 50 Ω
Resistance of water filter (R3) = 500 Ω
Potential difference of the source, V = 220 V
Since all the resistance are in parallel then the equivalent resistance R of the circuit will be

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All the three given appliances are drawing 7.04 A of current.
Therefore, current drawn by an electric iron connected to the same source of potential 220 V = 7.04 A
Let   Rʹ be the resistance of the electric iron. According to Ohm’s law,
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Therefore, the resistance of the electric iron is 31.25 Ω and the current flowing through it is 7.04 A.