Question

A+metal+wire+of+resistance+6ohm+is+stretched+to+twice+of+its+original+length.+Calculate+its+new+resistance.

Answer 1

Answer:

Explanation:Let original length area and resistivity of the wire be L, A and P .

We know that

R = PL/A

60 = PL/A. ......(1)

After stretching

Length becomes twice i.e. 2L

Therefore area will become half i.e. 1/2 A

New resistance,R'= P2L/A/2

R' = 4PL/A

R' = 4x60. ....(from 1)

R'= 240 ohm