Ask Question
17 July, 11:53

A 111 ‑turn circular coil of radius 2.11 cm and negligible resistance is immersed in a uniform magnetic field that is perpendicular to the plane of the coil. The coil is connected to a 14.1 Ω resistor to create a closed circuit. During a time interval of 0.125 s, the magnetic field strength decreases uniformly from 0.669 T to zero. Find the energy, in millijoules, that is dissipated in the resistor during this time interval.

+3
Answers (1)
  1. 17 July, 12:05
    0
    0.0061 J

    Explanation:

    Parameters given:

    Number of turns, N = 111

    Radius of turn, r = 2.11 cm = 0.0211 m

    Resistance, R = 14.1 ohms

    Time taken, t = 0.125 s

    Initial magnetic field, Bin = 0.669 T

    Final magnetic field, Bfin = 0 T

    The energy dissipated in the resistor is given as:

    E = P * t

    Where P = Power dissipated in the resistor

    Power, P, is given as:

    P = V² / R

    Hence, energy will be:

    E = (V² * t) / R

    To find the induced voltage (EMF), V:

    EMF = [ - (Bfin - Bin) * N * A] / t

    A is Area of coil

    EMF = [ - (0 - 0.669) * 111 * pi * 0.0211²] / 0.125

    EMF = 0.83 V

    Hence, the energy dissipated will be:

    E = (0.83² * 0.125) / 14.1

    E = 0.0061 J
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “A 111 ‑turn circular coil of radius 2.11 cm and negligible resistance is immersed in a uniform magnetic field that is perpendicular to the ...” in 📗 Physics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers