As a loop of wire with a resistance of 10Ω moves in a constant non-uniform magnetic field, it loses kinetic energy at a uniform rate of 4.0 ms/s. The induced current in the loop is:
Correct answer: C. 2.8 mA
- A. 0 mA
- B. 2 mA
- C. 2.8 mA
- D. 20 mA
Explanation
The induced current in the loop is 2.8 mA. The rate of loss of kinetic energy is equal to the power dissipated in the loop, which is given by the formula: P = I2R, where P is the power dissipated, I is the induced current, and R is the resistance of the loop.Given that the rate of power dissipation (P) is 4.0 mW and the resistance (R) is 10 Ω, we calculate the current as:I = sqrt(P/R) = sqrt(4.0/10) = 2.8 mA.Therefore, option C is correct. Options A, B, and D are incorrect as they do not correctly apply the formula to find the induced current.
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About Faraday's Law
Faraday's law states that an induced electromotive force equals the rate of change of magnetic flux linkage through a circuit. Questions cover changing field, area, angle or motion, the negative sign associated with Lenz's law, and the distinction between induced emf and the current that may flow in a closed circuit.
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