Question

A wire is cut into four equal parts. These parts are twisted to form one thick and small wire.
By what factor its resistance should be multiplied to get resistance of original wire?

Do it fast​

Answer 1

Answer:

A piece of wire of resistance r is cut into 4 equal parts. So, each of this part will have resistance equal to r / 4.

There are four parts of cut wire each with resistance equal to r / 4.

When these parts are connected in parallel, then equivalent resistance will be :------->

1 / R eq = 1 /( r/4 ) + 1 / (r/4 ) + 1/ ( r/4 ) + 1 / ( r/4 )

1 / R eq = 4 / r + 4 /r + 4 / r + 4 / r

1 / R eq = 16 / r

R eq = r / 16

Hence, the equivalent resistance of the combination when connected in parallel is r / 16.

Answer 2

Answer:

There are four parts of cut wire each with resistance equal to r / 4. Hence, the equivalent resistance of the combination when connected in parallel is r / 16.