Scribe Post MONDAY

Ugh almost forgot about this.

The Answers to the Electromagnetic Induction sheet

1. v = 100km/h x 1h/3600s x 1000m/1km = 280m/s

EMF = Blv = (5x10^(-5)*T)(70m)(280m/s) = 1.0V

2. EMF = Blv = (0.025Wb/m^2)(0.10m)(0.75m/s)

3. EMF = Blv = (0.45N/A*m)(0.15m)(0.3m/s)

= 2.0 x 10^(-2) V

4. EMF = Blv = (0.02T)(0.05m)(0.1m/s)

= 1 x 10^(-4) V

5. EMF = -N(delta phi/delta t) = -325 (1.15 x 10 ^(-5) WB / 1.0 x 10^(-3)s)

EMF = -3.74V

6. N = EMF/(deta phi/delta t) = 0.25V/((5x10^(-3))/1s) = 50 turns

7. phi = 8A

EMF = -N ((BA)/delta t) = -75 [ ( 1.5(Wb/m^2) x 4m^2 x ((m^2) / 10^4 m^2) / 2.5 x 10^(-2) s) ]

EMF = -1.8V

Reviewed Lenz's law, which basically states that the direction that the poles are moving in relation to the current changes wether the current flows clockwise or counterclockwise. Lenz's law states:

"For a current induced by a conductor by a changing magnetic field, the current is in such a direction that its own magnetic field opposes the charge that produced it."

In laymans terms, the current flows in a direction that causes the magnetic field to be the opposite of the field that created it.

We did a quick worksheet on Lenz's law, then got an exam review and a sheet on Transformers (robots in disguise). 

Study up for the exam!