The resistance of a wire is 5 ohm at 50 and 6 ohm at 100. The resistance of the wire at 0 will be (a) 3 ohm (b) 2 ohm (c) 1 ohm (d) 4 ohm

Answer: (d). Rt = R₀(1+α t): 5 = R₀(1+50α), 6 = R₀(1+100α). Dividing: 6 + 300α = 5 + 500α ⇒ α = 1/200 per ° C. R₀ = 5/1.25 = 4 Ω. The answer is (d).

The resistance of a wire is 5 ohm at 50 and 6 ohm at 100. The… | JEE Main 2007 (AIEEE)

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Ohm's Law, Resistivity & Temperature

The resistance of a wire is $5$ ohm at $50^\circ\text{C}$ and $6$ ohm at $100^\circ\text{C}.$ The resistance of the wire at $0^\circ\text{C}$ will be

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Answer: (d)

$R_t = R_0(1+\alpha t)$ : $5 = R_0(1+50\alpha)$ , $6 = R_0(1+100\alpha)$ .
Dividing: $6 + 300\alpha = 5 + 500\alpha \Rightarrow \alpha = 1/200$ per $^\circ$ C.
$R_0 = 5/1.25 = 4\ \Omega$ . The answer is (d).