3. The electrical resistance r of a wire varies directly with its length Test Image and inversely with the square of its diameter d. 100 m of wire with diameter 3 mm has resistance of 8 ohms. What is the resistance of 150 m of wire with diameter of 4 mm?

Question

3.	 The electrical resistance r of a wire varies directly with its length Test Image and inversely with the square of its diameter d. 100 m of wire with diameter 3 mm has resistance of 8 ohms. What is the resistance of 150 m of wire with diameter of 4 mm?

anonymous · Answer

Resistance= (Rho*Length)/Diameter
so first find the value of Rho by putting diameter=3mm, Resistance=8ohms and length 100m by following formula
Rho=(Resistance*Diameter)/length
the put the value of Rho, obtained, in the formula to find resistance for the second case.