A copper wire and an aluminium wire have the same length and same cros…

Question

A copper wire and an aluminium wire have the same length and same cross-sectional area. If ρ_Cu = 1.7 × 10⁻⁸ Ω m and ρ_Al = 2.6 × 10⁻⁸ Ω m, the ratio R_Cu / R_Al is

Accepted Answer

A. {'text': '0.65', 'label': 'A'}

1. R = ρ l / A, so with same l and same A, R is directly proportional to resistivity ρ.
2. R_Cu / R_Al = ρ_Cu / ρ_Al = 1.7 × 10⁻⁸ / 2.6 × 10⁻⁸.
3. Divide: 1.7 / 2.6 ≈ 0.654.
4. Aluminium has higher resistivity, so R_Cu < R_Al under equal geometry.
_Source: NCERT Class 12 Physics, Ch 3 "Current Electricity", §3.4_

Answer

{'text': '1.53', 'label': 'B'}

Answer

{'text': '1.00', 'label': 'C'}

Answer

{'text': '2.60', 'label': 'D'}