A copper wire has diameter 0.5 mm and resistivity of Chapter 12: Electricity Science Class 10 solutions are developed for assisting understudies with working on their score and increase knowledge of the subjects. Q 6: 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? is solved by our expert teachers. You can get ncert solutions and notes for class 10 chapter 12 absolutely free. NCERT Solutions for class 10 Science Chapter 12: Electricity is very essencial for getting good marks in CBSE Board examinations
Q 6: 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?
Ans: 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 
∴ length of the wire = 122.72m
If the diameter of the wire is doubled, new diameter=2×0.5=1mm=0.001m
Let new resistance be Rʹ 
∴ the new resistance is 2.5 Ω
Copyright @ ncerthelp.com A free educational website for CBSE, ICSE and UP board.
