Question

A wire of resistance 9 ohm having length 30 cm is
tripled on itself. What is its new resistance ?​

Answer 1

Answer:

If only length is changed, R(new) = 27 ohms.

Explanation:

If only length is changed, ie: volume is constant, then R changes directly with L^(1).

Answer 2

$\huge\bigstar\underline\pink{anSwer}$

★ R = rho × l/A

Given,

R = 9Ω

I = 30cm

rho/A = R/l

rho/A = 9/30 = 3/10.....(1)

Now,

For new resistance,

R' = (rho × l/3) / 3A........(2)

Substituting the value of rho/A from equation 1 in equation 2 we get ,

R' = (3 × 30/3) / 10 ×3

R'= 1Ω

Happy to help!

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