Your employer asks you to build a 15-cm-long solenoid with an interior field of

Question

Your employer asks you to build a 15-cm-long solenoid with an interior field of 4.4 mT. The specifications call for a single layer of wire, wound with the coils as close together as possible. You have two spools of wire available. Wire with a #18 gauge has a diameter of 1.02 mm and has a maximum current rating of 6 A. Wire with a #26 gauge is 0.41 mm in diameter and can carry up to 1 A. Which wire should you use? What current will you need? Express your answer to two significant figures and include the appropriate units.

Explanation / Answer

given requirement of field is 4.4mT

no. of turns for # 18wire =150/1.02 = 147 turns in 15 cm =980turns in 1m

no. of turns for # 26wire= 150 /0.41= 366 turns in 15 cm = 2440 turns in 1m

now, field in a solenoid is given by

B=mu*n*I

where n is the no. of turns per unit length

now,

for #18 ,

4.4x10-3 = 4*pi x10-7 *980 *I

=>I=3.57 A

for ,# 26 wire

4.4x10-3 = 4*pi x10-7 * 2440*I

=>I=1.43 A

we can see that #18 has the current within 6A

hence you should use #18 wire

where current is 3.57 A

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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