What is meant by resistance of conductor? Name and define its Sl unit. List the factors by which the resistance of a wire is affected. What happens if i] its length is doubled ii] its radius is doubled?

What is meant by resistance of conductor? Name and define its Sl unit.

1.	What is meant by resistance of conductor? Name and define its Sl unit. List the factors by which the resistance of a wire is affected. What happens if i] its length is doubled ii] its radius is doubled?
Answer» Solution :RESISTANCE is the property of the CONDUCTOR to resist the flow of current. Sl UNIT of Resistance is Ohm. Resistance of a conductor DIRECTLY depends upon Length of the wire L Inversely depends upon Area of Cross section of the conductor I/A Nature of material used. Therefore, `R=(rhoL)/A` Length of the conductor is double, means you are stretching that given length to double it. As a RESULT, the wire becomes thin due to stretching. So its area of cross section will be halved [since the volume remains constant]. So new resistance `R_(N)=(rho2L)/(A/2)=(4rhoL)/A=4R` Hence the new resistance will increase will become one-fourth.