Electromagnetic Induction

Question 0

Michael Faraday

Answer 0

Convicted that the reverse was possible: that a magnetic field could produce a current. He also wrote this goal in his notebook: “ Convert magnetism into electricity.”

Question 1

Electromagnetic Induction?

Answer 1

A changing magnetic field can induce current in a conductor

Question 2

Joseph Henry

Answer 2

A high-school teacher who later became the first secretary of the Smithsonian Institution, made the same discovery

Question 3

Induced electromotive force

Answer 3

Potential difference across the length of the wire

Question 4

INDUCED EMF: A straight wire is part of a circuit that has a resistance (R) of 0.50 Ω. The wire is 0.20m long and moves at a constant speed of 7.0 m/s perpendicular to a magnetic field of strength 8.0 x 10⁻²T.
A.What EMF is induced in the wire?

Answer 4

EMF = BLv

EMF = 0.11V

Question 5

INDUCED EMF: A straight wire is part of a circuit that has a resistance (R) of 0.50 Ω. The wire is 0.20m long and moves at a constant speed of 7.0 m/s perpendicular to a magnetic field of strength 8.0 x 10⁻²T.
B. What is the current through the wire?

Answer 5

I = EMF / R

I = 0.22A

Question 6

INDUCED EMF: A straight wire is part of a circuit that has a resistance (R) of 0.50 Ω. The wire is 0.20m long and moves at a constant speed of 7.0 m/s perpendicular to a magnetic field of strength 8.0 x 10⁻²T.
C. If a different metal were used for the wire, increasing the circuit’s resistance to 0.78 Ω, what would the new current be?

Answer 6

I = EMF/R

I = 0.14A

The current is counterclockwise

Question 7

Electric Generators

Answer 7

Converts mechanical energy to electrical energy

Question 8

Lenz’s Law

Answer 8

The magnetic field produced by the induced current is in the direction that is opposite the original field

Question 9

Eddy’s currents

Answer 9

Are current s generated in any piece of metal moving through a magnetic field; the magnetic field they produce opposes the motion the metal in either direction

Question 10

Self-inductance

Answer 10

The property of a wire, either straight or in a coil, to create an induced EMF that opposes the change in the potential difference across the wire

Question 11

Transformers

Answer 11

Devices that increase or decrease potential differences with relatively little waste of energy

Question 12

Mutual inductance

Answer 12

An EMF and current in one coil due to changing current in another coil

Question 13

Transformer Equation

Answer 13

Is / Ip = Vp / Vs = Np / Ns