A physics project needs an 8Ω resistor to be fabricated from a single 1.5m long wire of manganin whose resistivity is 44×10−8Ωm. Answer the following.
a. (i) Calculate the cross-sectional area that the wire must have so that its resistance equals 8Ω.
b. (ii) Hence find the required diameter of the wire.
c. (iii) Ready-made manganin wire is available only in diameter 0.30mm. If this wire is used without changing the length, compute the resistance obtained and state whether it satisfies the project requirement, giving suitable reasoning.