Question

A 4 ohm resistance wire is doubled on it. Calculate the new resistance
of the wire.​

Answer 1

Answer:

it will be 8 resistance

Answer 2

Given :-

• R = 4 ohms.

To be calculate :-

• New resistance of the wire.

Solution :-

We are given ,

R = 4 ohms .

When a wire is doubled on it , it's length would become half and area of cross would double . That is , a wire of length " l " and area of cross section A change to length l/2 and area of cross section 2A .

As you know ,

• R = PL/A 

R' = P(L/2) / 2A

Where R' is the new resistance .

So,

R'/R = {P(L/2) / 2A} / {PL/A} 

After calculating , we get :-

 R' /R = ¼ 

=> R' = R/4

= 4/4

= 1 Ohm.

Hence , the required new resistance of the wire is 1 Ohm.

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