A very small circular metal ring of radius r = 0.5 cm and resistance x = 5 Ohm i

Question

A very small circular metal ring of radius r = 0.5 cm and resistance x = 5 Ohm is at the center of a large concentric metal ring of radius R = 50 cm. The two rings lie in the same plane. At t = 3 s, the large ring carries a clockwise current of 3 A. At t = 3.2 s, the large ring carries a counterclockwise current of 5 A. (a) What is the magnitude of emf in the inner ring? (b) What is the magnitude and direction of the average current in the small ring? (c) What is the average electric field in the small ring during this time? Give both the magnitude and direction of the electric field.

Explanation / Answer

Given

r = 0.5 cm

R = 50 cm

Resistance x = 5 ohms

At t= 3s, large ring carries a current, I2 = 3 A (clockwise)

At t = 3.2 s, lage ring carries a cuurent, I2 = 5 A (counter clockwise)

a) Magnitude of the the emf in the inner ring = u/4pi() *( effective I)^2 /r

= 1.256/4*3.14* (5-3)/(0.5/100) = 395 V

b) Magnitude of current in Inner ring = ( 5-2) = 3 A

Since higher magnitude current is counter clock wise hence the direction of current in inner ring will be counter clock wise.

c) Average electric field = emf/ effective current = 395/ (5-2) = 395/3 = 131.6 N/C

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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