Question

Two wires of Copper (Cu) and Aluminium (Al) have the same lengths
and resistances. Given relative densities of Cu and Al as 8.9 and 2.7.
The resistivities of Cu and Al are 1.7 X 10-8 ohm meter and 2.6 X 10-8
ohm meter respectively. Compare the masses of Cu and Al respectively.

Answer 1

Explanation:

we know that the atomic mass is the sum of no. of protons and no. of neutrons present in a nucleus and hence the atomic mass of copper is 64u and mass of aluminium is 27u and therefore there ratios will be:- 64:27

Answer 2

hey mate here is your answer

Resistivity of aluminium, ρAl = 2.63 × 10−8 Ω m Relative density of aluminium, d1 = 2.7 Let l1 be the length of aluminium wire and m1 be its mass. Resistance of the aluminium wire = R1 Area of cross-section of the aluminium wire = A1 Resistivity of copper, ρCu = 1.72 × 10−8 Ω m Relative density of copper, d2 = 8.9 Let l2 be the length of copper wire and m2 be its mass. Resistance of the copper wire = R2 Area of cross-section of the copper wire = A2 The two relations can be written as It can be inferred from this ratio that m1 is less than m2. Hence, aluminium is lighter than copper. Since aluminium is lighter, it is preferred for overhead power cables over copper.

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