Length of a cylindrical metal bar (or wire) is increased. Does it have any effect on its cross sectional area?

Question

I exactly want to know if it is possible to increase the volume of a metallic wire, only by increasing the length and keeping the cross sectional area constant. Is it not possible by applying an axial load ?

Answer 1

A piece of wire is always going to have the same volume.

If you stretch it longer, it gets thinner, i.e. its cross section is reduced.

If you scrunch it shorter, it has to get fatter. However, it is hard to compress wire!

Any time you change one dimension, the other dimensions have to change too, in order for it to keep the original volume.

Answer 2

by applying axial load which is lesser than the yield strength of the metallic wire we can expand it elastically even at this point care should be taken not to cross the yield stress at which point the material will undergo reduction in cross section.

if within the elastic limit of the wire we apply a load the resilience will be there in the material just as in a spring without
altering the volume it will expand in length and contract in cross section, the effect will be reversible once we remove the static load, wherein the material regains its original area of cross section and original length.

but this only proves that the material wire cannot be expanded even within its elastic limit without changing the cross section, then volume remains unaffected.

Answer 3

Volume=pi x r^2 x L so if you increase the length cross sectional area must be smaller.

Answer 4

Yes it will affecvt the crossectional area. Since wire is same only redrawn therefore volume in both cases will be same. Let original area = A New Area = A' original length= L New Length = 2L Original volume = New Volume (original area)*(Original length)=(new area)*(new length) A*L = A' * (2L) A=2A' A' = A/2 Thur area is reduced to half of original area

Answer 5

If you only increase the length of a cylinder, the volume will increase. This is if you don't extrude the wire. If you apply any load to the wire it will contort but the volume will remain the same.

Answer 6

Only if you can find a way to expand it rather than stretch it. Heating it causes it to expand a little. Perhaps you could find a way to make it porous like a sponge. When pulled, most metals either stretch (increasing length, reducing cross-sectional area) or break.

Answer 7

we can increase a length of a wire by stretching.when we are strething, the volume of the wire will be same .The area of cross section will reduced or thinner

Answer 8

Hey that's simple . If you are not adding any new mass , how will the volume change?(Provided no change in system's configruation)
If the volume is constant,
V= (area of cross sec)*Length
hence if one of the two factors increases the other automatically decreases......clear???

Answer 9

nope.wen length is increased, the cross-sectional area does not change.

Answer 10

If we say at constant temp and pressure than surely no as any material is conserved u could not create or distroy it unless a nuclear reaction is involved. however if temperature is increased or surrounding pressure(atmospheric in our sense) is decreased volume will change.