Wires used in electrical circuits usually have low resistances so that as much as possible of the e.m.f supplied by source can be used by the components o fcircuit. Why are thicker wires not used? (after all, they have low resistance)
I need some assistance here.
Cost?
Is it practical?
depends on the applications...considering weigh, space and cost. and the different in resistence... how much thicker do you need to make the difference.
resistence will be considered if you need to carry very high current.
example 1:
your souce is 10V and your wire have a resistence of 0.1 ohms. If you design it to carry 1 Amp your voltage drop will only be 0.1V
by doubling the cross-sectional area you cut down resistence to 0.06 ohms. Your voltage drop will be 0.06V.
the difference will only be 0.04V... is this 0.04V different important?
your end load will still receive 9.96V.
example 2:
now your 0.1 Ohms wire need to carry 50 Amp.
voltage drop will be 5V across wire, your end load receive only 5 V then...
by doubling cross-sectional area, resistence drop to 0.06 ohms. your voltage drop across wire will only be 3 V
so by changing wire size you recover 2V, which does make some different...
In short... as what the other forumers has said
1) Cost and practicality
2) Does it affect your circuit functions much
For 2), for sensitive circuits, especially on circuit boards (those green green board things u see in computers), it is sensitive enough at times to warrant the use of gold as electrical connections