Question

Wire of resistance 4 ohm is strectched double it's length . find the resistance after it's strectched.

Answer 1

Resistance is directly proportional to l
new resistance=4*(2l/l)
=4*2

=8ohm

Answer 2

heyy frnd ☺☺

==========================
your's answer is given below:--

☆we know that ,

R=pL/A. (p=Rho)
then,

R= 1 × 1/1.
(if we assumed,Rho=1 , A = 1m2, L=1 m)

R= 1 ohm .
》》Now,

R= 1 × 2 / 1 .
(if we double of the length of wire,
then,L=2m)

SO,
new resistance = 2 ohm.

▪ from the above observation we concluded that if we double the length of wire , the resistance get also doubled).
SO,

final resistance = 4 × 2 = 8ohm.

8 ohm is the resistance after stretch.
=================================

Hope it helps⤴