Problema Solution
The electrical resistance of a wire R varies directly at its length L and inversely as its cross sectional area A. Use this information to answer the following questions.
a. If R = 0.2ohm, A=0.05in2 and L= 200ft, find the constant of proportionality
b. Find the resistance of a wire whose length is 5000ft with a cross sectional area of 0.01in2
Answer provided by our tutors
So R = K L/A
(a) K = RA/L = 0.2*0.5/ 200 = 0.00005
(b) R = (0.00005)* 5000/ 0.01 = 2.5 ohm