A copper wire has diameter 0.5 mm and resistivity of 1.6 × 10–8 Ω 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?
Resistance (R) of a copper wire of length l and cross-section A is given by the expression,
Where,
Resistivity of copper, p = 1.6 x 10-8 Ω m
Area of cross-section of the wire,
Diameter = 0.5 mm = 0.0005 m
Resistance, R = 10 Ω
Hence, length of the wire,
If the diameter of the wire is doubled, new diameter = 2x0.5 = 1 mm = 0.001 m
Therefore, resistance R'
Therefore, the length of the wire is 122.7 m and the new resistance is 2.5 Ω
Match Group (A) with Group (B)
| Group (A) | Group (B) |
|---|---|
|
(a) Autotrophic nutrition |
(i) Leech |
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Welcome to the NCERT Solutions for Class 10 Science - Chapter . This page offers a step-by-step solution to the specific question from Excercise 8 , Question 6: A copper wire has diameter 0.5 mm and resistivity of 1.6 × 10–8 Ω m. What will be ....
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