Question

In a series electrical circuit comprising a resistor made up of a metallic wire,
the ammeter reads 100 mA. If the length of the wire is doubled, how will
the current in the circuit change? Justify your answer.

Answer 1

Answer:

100length

Explanation:

becaude 100 length 56 in devided77

Answer 2

Answer:

The answer is 50mA

Explanation:

Let i₁ = 100mA

You have to assume that the wire is not stretched. So when the length is doubled the resistance will also be doubled.

                                        => R ∝ l

                                        =>R₂ = 2R₁  

                                        =>R₁ = R₂/2

From Ohm's law,

V = R₁i₁ => V = R₂/2(100)

=> V = 50R₂

                         ∴ V = R₂i₂ => 50R₂ = R₂i₂

                                        => i₂ = 50mA