Question

ad A wire of Length 10cm is starched to 20 cm the resistance of streched​

Answer 1

Explanation:

Given length of the wire is = 10 cm

After stretching it becomes 20 cm

Then the new resistance of the wire will be,

R = ¶ l/A

where,

'R' is the resistance of the wire

'¶' (rho) is the resistivity of the material

'l' - is the length of the wire

'A' is the cross sectional area of the wire

The stretched wire volume will remain constant

V = l × A

'V's the total volume of the wire

=> A = V/l

Thus, R = ¶ l/V×l = ¶ l^2/V is directly proportional to l^2

Since, the length of the wire doubles, the resistance will become 4 times.