# The resistance of a wire is 20 ohm.it is so streched that the length becomes 3 times then what is the new resistance of the wire? any one there who can give right answer

2
by shv

2014-09-29T21:07:23+05:30
Sol: When a wire of length l1 and resistance R1 is stretched to l2, then new resistance is R2 = 502,R1(l2/l1)2. R2 = R(n)2 since l2 = nl1.
hope it would be useful !!!!
oopss........... i'm really sorry !!!!!!!
Q:A wire of resistance R is stretched so that its length
increases n times. What is its resistance?
Sol: When a wire of length l1 and resistance R1 is
stretched to l2, then new resistance is R2 =
50
2,
R1(l2/l1)2. R2 = R(n)2 since l2 = nl1.
• gel
• Ambitious
2014-09-29T21:48:14+05:30
R1=20 OHM                 L1=L1
R2=?                            L2=3L1

We know that, R  to l
therefore R2/R1 = L2/L1 ⇒R2/20=3L1/LI ⇒R2=20*3 ⇒R2 =60