All Flashcards
What are the differences between Faraday's Law and Lenz's Law?
Faraday's Law: Quantifies the induced EMF based on the rate of change of magnetic flux. | Lenz's Law: Determines the direction of the induced EMF, opposing the change in flux.
Compare voltage step-up and step-down in transformers.
Step-Up: More loops on the secondary side, increases voltage. | Step-Down: More loops on the primary side, decreases voltage.
What are three ways to change magnetic flux?
- Changing the magnetic field strength (B). 2. Changing the area (A) of the loop in the field. 3. Changing the angle (θ) between the field and area.
Describe how a motional EMF flashlight works.
A metal bar moves, sweeping area A = lΔx. The increasing area increases magnetic flux (ΦB = ∫ B ⋅ dA = BA). The induced field opposes this. Using RHR #2, the current flows CCW.
How can magnetic flux be changed?
- Changing the magnetic field strength (B). 2. Changing the area (A) of the loop in the field. 3. Changing the angle (θ) between the field and area.
Describe how a motional EMF flashlight works.
- A magnet moves through a coil of wire. 2. The changing magnetic flux induces an EMF. 3. The EMF drives a current, lighting the bulb.
What is the process of electromagnetic induction?
- A changing magnetic field is present. 2. This changing field induces a voltage (EMF). 3. If a closed circuit exists, the EMF drives a current.