Question

Which of the following can produce maximum induced voltage?

• A. 1A DC current
• B. 50A DC current
• C. 1A, 60Hz AC current
• D. 1A, 500Hz AC current

Hint:

To maximize induced voltage, use higher frequency AC currents. A higher frequency means a faster change in the magnetic field, leading to a greater induced voltage.

Answer 1

The Correct Option is D

The induced voltage in a conductor is given by Faraday’s law of induction, which states that the induced voltage is directly proportional to the rate of change of magnetic flux.
For a time-varying current, the induced voltage is given by the formula: \[ V = N \frac{d\Phi}{dt} \] Where: - \( N \) = Number of turns of the coil (not relevant in this case)
- \( \frac{d\Phi}{dt} \) = Rate of change of magnetic flux
The rate of change of flux is higher for alternating currents (AC) than for direct current (DC) because the direction and magnitude of AC current change continuously, especially at higher frequencies.
- A DC current produces a constant magnetic field, leading to zero rate of change of flux once the current reaches steady state.
- AC currents, on the other hand, generate a changing magnetic field which induces voltage.
Therefore, to produce the maximum induced voltage, the frequency of the AC current should be as high as possible.
Thus, 1A of 500Hz AC current will produce the maximum induced voltage because it has the highest frequency compared to the other options.