How does the resistance of a wire change when area of cross section is doubled?
Answers
Answer:
Explanation:
Resistance is directly proportional to the length of the wire, and inversely proportional to the cross sectional area of the wire.
R = pl/A, where R is resistance, p is the material's resistance in ohms, l is the length, and A is the cross sectional area in m^2.
As a wire gets longer its resistance increases, and as it gets thinner its resistance also increases because its cross sectional area decreases.
Doubling the length will double the resistance, but the wire also must get thinner as it is stretched, because it will contain the same amount of metal in twice the length. The volume of a cylinder is length * cross sectional area, but in order to find the new cross section, you need to consider what the wire is made of. Most materials resist a change in volume more than they resist a change in shape, and because of that, they lose less volume than otherwise would be expected when stress is applied.
Answer:
the resistance is halved.
Explanation:
because resistance is inversely proportional to area of crossection.more current will be able to flow