Question

23. calculate the resistance of I km long copper wire of radius imm. Resistivity of the copper is 1.72*10^ * 12.m b Draw a schematic diagram of a circuit consisting of a battery of 4 cells of 2v each connected to a key, an ammeter and two resisters of 242 and 32 respectively in series and a voltmeter to measure potential difference across 342.​

Answer 1

Explanation:

Solution :

Length of copper wire(l) = 1 km = 1000 m

Radius of the copper wire(r) = 1 mm = 1 x 10^-3 m

Resistivity of the copper (p) = 1.72 x 1 0-8 W m

Area of cross section = pi * r^2 = 3.14 x 10^-3 x 10^-3 = 3.14 x 10^-6

R = pl/A = (1.72 x 1 0-8 x 1000 ) / 3.14 x 10^-6 = 5.5