Two rods joined end to end, each of length 1 m and cross-sectional area 0.01 cm². One copper rod resistivity 1.7 × 10⁻⁶ Ω·cm and one iron rod 10⁻⁵ Ω·cm. Voltage required to produce 1 A is: [Diagram: Image]
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Question

Two rods joined end to end, each of length 1 m and cross-sectional area 0.01 cm². One copper rod resistivity 1.7 × 10⁻⁶ Ω·cm and one iron rod 10⁻⁵ Ω·cm. Voltage required to produce 1 A is: [Diagram: Image]

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G1 Physics · Accepted Answer

Step 1: Convert area A=0.01 cm². Resistivity given in Ω·cm; length L=100 cm. Step 2: Total series resistance = (ρ𝒸ᵤ+ρ𝒻ₑ)L/A = (1.7×10⁻⁶+10⁻⁵)×100/0.01 = 0.117 Ω. Step 3: V = IR = 1×0.117 = 0.117 V.