The resistance of a wire of length 250 m is 1 ohm. If the resistivity of the material of wire is 1.6
x 10–8
ohm meter, find the area of cross-section of the wire. How much does the resistance
change if the diameter is doubled?
Answers
Answered by
2
resistance = resistivity * length / area
=>1 = 1.6 * 10 ^ -8 * 250/area
=>area = 400 * 10 ^ -8
=> area = 4*10^-6 m^2
If the diameter is doubled then the radius of area of cross-section will be doubled
which means resistance will be 4 times since the radius is to be squared.
=>1 = 1.6 * 10 ^ -8 * 250/area
=>area = 400 * 10 ^ -8
=> area = 4*10^-6 m^2
If the diameter is doubled then the radius of area of cross-section will be doubled
which means resistance will be 4 times since the radius is to be squared.
Mamtabagrecha:
1.6*250 = 400 and not 4000.
yes you are right
did a mistake
and resistance is inversely proportionate to area of cross section, since area increases by 4 times, resistance will decrease by 4 times, hence the new resistance will be 0.25 ohm.
Similar questions