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.
