22.5, 22.8, & 22.9

Mutual induction occurs when:

• an AC current produces a changing magnetic field which produces a change in magnetic flux within 1 coil, creating induced emf.

• an induced emf resulting from a change in magnetic flux leads to an induced current, which produces a magnetic field.

• magnetic field lines from a primary coil pass through a secondary coil, creating induced emf

• electric field lines from a primary coil pass through a secondary coil, creating induced emf

Self induction occurs when:

• an AC current produces a changing magnetic field which produces a change in magnetic flux within 1 coil, creating an induced emf.

• an induced emf resulting from a change in magnetic flux leads to an induced current, which produces a magnetic field.

• magnetic field lines from a primary coil pass through a secondary coil, creating induced emf

• electric field lines from a primary coil pass through a secondary coil, creating induced emf

A transformer is an example of ___________ induction and you need ______ current in order for it to work.

• mutual; DC

• self; DC

• self; no

• mutual; AC

• L = length of coil (m)

• L = self inductance (Wb)

• L = self inductance (H)

• L = length of coil (cm)

Lenz's law states that an induced current will flow in such a way that is produces a magnetic field to ______________________ the change in flux.

• share

• minimize

• oppose

• change

According the Lenz's Law,

if the original magnetic field is ___________________, the induced magnetic field must point in the __________________ direction.

• increasing; same

• decreasing; same

• increasing; opposite

• decreasing; opposite

Steps to using Lenz's Law:

1. 1. Determine whether the ______________________ is increasing, decreasing, or not changing.

• induced magnetic field

• induced current

• original magnetic field

• electric field

Steps to using Lenz's Law:

2. 2. Apply Lenz's Law to determine if the _________________________ will be in the same direction or in the opposite direction of the original magnetic field.

• induced current

• induced magnetic field

• current

• electric field