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Three resistors 2 Ω, 4 Ω and 5 Ω are combined in parallel. What is the total resistance of the combination?

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#### Solution

There are three resistors of resistances,

R_{1} = 2 Ω, R_{2} = 4 Ω, and R_{3} = 5 Ω

They are connected in parallel. Hence, total resistance (R) of the combination is given by,

`1/"R" = 1/"R"_1 + 1/"R"_2 + 1/"R"_3`

= `1/2 + 1/4 + 1/5`

= `(10 + 5 + 4)/20`

= `19/20`

∴ R = `20/19` Ω

Therefore, the total resistance of the combination is `20/19` Ω.

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