Question

A copper wire has a resistance of 0.6 ohm . Another copper wire of same mass as forst one is doubled in length of the first.
Find the resistance of the second wire.
ans is 2.4

the one who gave effective explanation
is awarded as brainlist ​

Answer 1

Resistance of second wire = 2.4Ω

Step-by-step explanation:

Given:

Resistance of first wire = 0.6Ω

Length of second wire = 2(Length of first wire)

Note:

We know that when length of wire is doubled , the area is halved.

So,

Area of Second wire = Area of first wire / 2 = 0.5 Area of first wire

Computation:

Resistance of first wire = 0.6Ω = p(Length of first wire) / Area of first wire

Resistance of second wire = p(Length of Second wire) / Area of Second wire

Resistance of second wire = p × 2(Length of first wire) / 0.5 Area of first wire

Resistance of second wire = 4 × p(Length of first wire) / Area of first wire

∵ [0.6Ω = p(Length of first wire) / Area of first wire]

Resistance of second wire = 4 × 0.6Ω

Resistance of second wire = 2.4Ω