Question

two copper wires A and B of length 30 M and 10 m have the radii of 2 cm and 1 cm respectively compare the resistance of two wires which will have the less resistance​

Answer 1

Answer:

Explanation:

As both the wires are of same material, therefore their resistivity will be same.

Now, the length of wire A= 30m=L

Radius of wire A=2cm=0.02m

Area of wire=pie*r*r=A

Area of wire A=pie*0.02r*0.02r

= 0.0004r*square pie

=0.0004A

Reaistance of a wire=resistivity*L/A =R

Resistance of wire A= 30L/0.0004A=7500R

Similarly, resistivity of wireB=10L/0.0001A=10000R

So resistance of wire B is more than wire A

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