Question

a uniform wire of resistance 50 ohms is melted and recast into a wire of length half that of the original what would be the resistance of the new wire formed?​

Answer 1

Answer:

the resistence of the new wire be get half

Explanation:

bcoz the resistance of wire is directly proportional to the length of the wire

Answer 2

Let us look at the answer:

Explanation:

The resistance depends on various factors :

• resistivity , ρ
• length of the conductor, l
• Area of cross-section of the wire, A=πr²

                 R= ρ l/A , ρ - constant for a specific material.

R = 50 ohms.

we are required to find the new resistance of the wire, whose length is half the previous ⇒l₁ = l/2 and radius of cross-section of wire, r₁ = 2r

⇒A₁= πr₁² = π (2r)²

Therefore R₁= ρ l₁/A₁ = ρ l/2 ÷ π (2r)²

        R₁= R/8 = 50/8 = 6.25 ohms