Define electric resistance of a conductor? (b) List two factors on which resistance of a conductor depends. (c ) Resistance of a metal wire of length 1m is 104 Omega at 20^@C. IF the diameter of the wire is 0.15mm, find the resistivity of the metal at that temperature.

Define electric resistance of a conductor? (b) List two factors on wh

1.	Define electric resistance of a conductor? (b) List two factors on which resistance of a conductor depends. (c ) Resistance of a metal wire of length 1m is 104 Omega at 20^@C. IF the diameter of the wire is 0.15mm, find the resistivity of the metal at that temperature.
Answer» Solution :(C )Here length of wire L=1m, resistance R=`104 Omega` and DIAMETER of wire D=0.15mm =`0.15 TIMES 10^-3 m` As per relation `R=(rho L)/A=(4 rho L)/(PI D^2)`, we have Resistivity `rho = (pi D^2 R)/(4 L)=(22 times (0.15 times 10^-3)^2 times 104)/(7 times 4 times 1)=1.84 times 10^-6 Omega. m`