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?

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# 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?

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## Brainigniter

R_{1}= 100 ΩR_{2}= 50 ΩR_{3}= 500 ΩSince, all three appliances are connected in parallel;^{1}/_{R}_{p}=^{1}/_{R}_{1}+^{1}/_{R}_{2}+^{1}/_{R}_{3}^{1}/_{R}_{p}=^{1}/_{100}+^{1}/_{50}+^{1}/_{500}^{1}/_{R}_{p}=^{16}/_{500}R_{p}=^{500}/_{16}= 31.25 ΩNow, R = 31.25 Ω and V = 220 VUsing Ohm’s law,I =^{V}/_{R}=^{220}/_{31.25}= 7.04 AHence, the resistance of the electric iron is31.25 Ωand the current flowing through it is7.04 A.