Question

A wire of given material having length l and area of cross-section 'A' has a resistance of 27 ohms. What would be the resistance of the same material having length l/3 and area of cross-section 3A?​

Answer 1

Explanation:

here is ur ans bro

hope it hlps

Answer 2

Answer:

given:

length = l

area of cross-section = A

R = 27ohms

so, the formula is =

R = ∫×l/a......(i)

⇒ ∫ = R×a/l.....(ii) ( derived from i)

so, substituting values into equation (ii),

⇒∫ = 27A/l...(iii)

So, the given values of the new wire,

length = l/3

area of cross-section = 3A

∫ = 27A/l ( from iii)

So, new resistance,

R = 27A/l × l/3 × 1/3A

⇒R = 27/9

⇒R = 3ohms

∴ The resistance of the new wire is 3ohms.