You have a summer job in the University ecology lab. Your supervisor asks you to

Question

You have a summer job in the University ecology lab. Your
supervisor asks you to duplicate an electromagnet that she has
borrowed. She tells you that this electromagnet is made by wrapping a
wire many times around a piece of iron and provides you with all the
parts, the same type of wire of the same diameter and an identical iron
core. What you need to know is how much wire to wrap around the
iron. Unfortunately, you cannot simply unwrap the wire from the
borrowed magnet because that will destroy it. On the side of the
electromagnet, it tells you that when a potential difference of 12 V is
put across the ends of its wire, there is a current of 0.06 A through the
wire. With a brilliant flash of insight, you realize that the crosssectional area and the conductivity is the same for both the magnet's
wire and the wire you have, so you can find the length with a simple
experiment. You cut off a 100-foot piece of identical wire from your
supply, attach it to a 1.5-V flashlight battery and measure a current of
0.10 A through that wire. Eureka! you can now find the length of the
magnet's wire

Explanation / Answer

E = K P L I / A where K = specific resistivity (Ohm - circular mils/foot) P = phase constant = 2 (single phase) = 1.732 (three phase= L = wire length (ft) A = wire area E = K P L I / A

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.