AS Physics Hw by tomorrow
Resistivity
A coil of constantan wire of length 2 m has an area of cross-section of
7 x 10-7 m2. If its resistivity is 49 x 10-8 Ω m, find its resistance.
A coil of wire 4 m long has a resistance of 20 Ω. If its resistivity is
108 x 10-8 Ω m, find its area of cross-section.
A 1.75 m length of tin wire with a diameter of 0.70 mm is found to have a resistance of 0.5 Ω Find the resistivity of tin.
A resistor of 2 Ω is to be made from manganin wire of resistivity
42 x 10-8 Ω m having a diameter of 0.42 mm. What length is required?
Find the resistance of a wire 2.8 m long with a resistivity of 22 x 10-8 Ω m and a diameter of 0.56 mm.A wire has a resistance of 2 Ω Find the resistance of a wire of the same material which is three times as long, but with half the diameter.
