Question

(1) A wire of 3 ohm resistance and 10 cm length is stretched to 30 cm length.What will be its new resistance?(2) A wire of 9 ohm resistance having 30 cm length is tripled on itself. What is its new resistance?

Answer 1

1) I will tell ua simple formula
R new = n*nR original
n is the number of times wire is stretched of original okkk
Now R new = 3*3*3
R new = 27ohm
2) if length of wire is tripled then resistance Is also tripled as length of wire is directly proportional to resistance of wire
so R new = 9*3 = 27ohm