A copper wire has diameter 0.5 mm and resistivity of 1.6 � 10−8Ω
m. What will be the length of this wire to make its resistance 10 Ω? How much
does the resistance change if the diameter is doubled?
A copper wire has diameter 0.5 mm and resistivity of 1.6 � 10−8Ω
m. What will be the length of this wire to make its resistance 10 Ω? How much
does the resistance change if the diameter is doubled?
Answer
Area of cross-section of the wire, A =π (d/2) 2
Diameter= 0.5 mm = 0.0005 m
Resistance, R = 10 Ω
We know that
Therefore, the length of the wire is 122.7 m and the new resistance is 2.5 Ω.
