A tightly coiled spring having 76.0 coils, each 3.62 cmin diameter, is made of insulated metal wire 3.27 mm indiameter. a)An ohmmeter connected across opposite ends of the springreads 1.73 . What is the resistivity of the metal? = .m A tightly coiled spring having 76.0 coils, each 3.62 cmin diameter, is made of insulated metal wire 3.27 mm indiameter. a)An ohmmeter connected across opposite ends of the springreads 1.73 . What is the resistivity of the metal? = .m
Explanation / Answer
R=L/A where A iscrosssectional area of conductor and L is the length and theresistivity. Therefore, =RA/L One coil length is its circumference D whereD=.0362m. So total length of wire is L=76(D)=2.7512m A=r2 whre r=3.27x10-3/2or r=1.635x10-3 and A=2.673x10-6()m2 =(1.73)(2.673x10-6)/2.7512 =1.68x10-6 m = =