A composite conductor 10 m long consists of an inner core of steel of radius 1.5 cm

Question:

A composite conductor 10 m long consists of an inner core of steel of radius 1.5 cm and an outer sheath of copper whose thickness is 0.5 cm.
(a) Determine the resistance of the conductor.
(b) If the total current in the conductor is 60 A, what current flows in each metal?
(c) Find the resistance of a solid copper conductor of the same length and cross-sectional areas as the sheath. Take the resistivities of copper and steel as 1.77 X 10–8 and 11.8 X 10–8 Ω ∙ m, respectively.