Answer to Question #65471 in Electric Circuits for Helen

Question

You were given a pendant on Valentine’s Day, and you wonder whether it is worth
anything more than emotional value. You attach it to a 1.50 V battery along with an
ammeter in series so that you can measure the current through the pendant, which
turns out to be a whopping 4.72×105 A. Based on the pendant being 2.00 cm long and
having an assumed cross section of 1.00 cm2
, determine the resistivity of the pendant.
Use Table 17.1 of your textbook to find out what substance your pendant is made of
(and assume you did your measurement at the reference temperature of 20.0◦ C).

Answer 1

R=U/I= k*L/S; k =(U*S)/(I*L), [k]=Ohm*m
K=1.5*0.02/(47.2)= 0.000636 Ohm*m
According to table data: material is Wolfram