Question

An electric lamp of 100Ω, a toaster of resistance 50Ω and a water filter of resistance 500Ω 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 1

Resistance of Electric 1 amp R₁ = 100Ω

Resistance of Tosser, R₂ = 50Ω

Resistance of water filter, R₃ = 50Ω

Potential difference, V = 220V

When these are connected in parallel,

7.04A of electricity is obtained by three appliances

Resistance of an electric iron connected to the same source that takes as much current as all three appliances

220 V = 7.04 A

As per ohm's law

V = IR¹

∴ R¹ = \(\frac{V}{I}\)

= \(\frac{220}{7.04}\)

= 31.25Ω

∴ Resistance of iron box = 31.25Ω

Electricity flowing through this = 7.04A.