(b), (d). The length of the line cord will double in this event. This would tend to increase
of the line cord. But the doubling of the radius of the line cord results in the
increase of the cross-sectional
area by a factor of 4. This would reduce the resistance more than the doubling of length increases it. The net result is a
decrease in resistance.
The same effect would occur for the lightbulb filament. The lowered resistance would result in a larger current in the
filament, causing it to glow