The resistance in a wire increases when the length of the wire increases. Write the correct equation for this scenario and solve for when the length is 1.

Question

The  resistance in a wire increases when the length of the wire increases. Write the correct equation for this scenario and solve for when the length is 1.

mathmale · Answer

This situation is one of "direct proportion," where the dependent variable (here, the resistance of the wire to current flow) is directly proportional to the independent variable (here, the length of the wire).  Thus, if r= the resistance, l = the length of the wire, and k = a constant of proportionality (which here is unknown), 

r(l) = k*l.    Note that r(l) denotes resistance as a function of length.

mathmale · Answer

Again, we don't know the value of k.  So, to answer the 2nd part of this question, borrow the equation I gave you (above) and substitute only the given value of the independent variable, l (the length of the wire).

anonymous · Answer

R = .2L; R = 5?

mathmale · Answer

At this time we have no numerical values for anything, so it's not possible to come up with answers as specific as R = 0.2L or R = 5.