I did some experiment about Faraday’s Law of Induction. In part A I did experime

Question

I did some experiment about Faraday’s Law of Induction.

In part A I did experiment like this.

I drop the wand in some particular height and got the graph of voltage and average of voltage(just first peak) by computer and calculate ?B.

1. In my experiment, the first pick of the voltage graph have positive sign, and the second pick of the voltage graph have negative sign. Why the second peak have opposite sign about the first one?

2. When wand passes the center of magnet, the value of voltage was almost 0V. Why?

3. When the angle between wand (the position that drop the wand) and the central axis become bigger, the value of average voltage of first peak become lower. Why?

4. When the interval of the magnet plate becomes bigger, the value of average voltage of first peak becomes bigger too. Why?

In part B, I removed the magnet plate (the magnet poles are remain. Just remove the plate.). And I did experiment twice. First, do this experiment without resister to get the value of energy lost by friction (mechanical loss). second, do this experiment with resister to get the value of energy lost by resistors (thermal dissipation loss).

1. I just did experiment by manual, but I really don’t understand why I dothis experiment. Please explain why I do this experiment. And why remove the magnet plate in this part?

Explanation / Answer

Solution:

The experiment is about Faraday's law of induction .

Faraday's law of induction .tells usabout the interaction of a magnetic field with an elctric circuit/field produce anelectromotive force. (EMF).

the magnet plate removal is to show the change in emf (voltage) generated when a magnetic field changes.

In this experiment Voltage is produced only when the field changes.

1. As he induced emf increases in the 1st part, the peak has a positive value and during the decrease, the peack has the opposite sign.

2. The magnetic field of a agnet at its center is null or zero and the field is always strongest at the poles (ends) of a agnet . So it is zero.

3. Since the magnetic flux is related as area X magnetic field x cos theta , the value decreases as the angle increases.

4. When the time interval INcreases , that is if it takes , say for example 10 seconds to induce the field instead of 5 or 6 seconds the emf induced will be lesser and the voltage peak spreads out.

The delta U in the energy change. Your expressions shown above are correct. The energy is basically potential energy ; as the hi and hf indicate.

The Area under the power - time curve gives energy ; This is understood fromthe basic definition of power : It is the rate of change in energy.

Power = energy/ time => Energy = Power x time.

And from the P-t curve , it is the area that determines the Energy .

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

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