P11 EM (7) - Generators and transformers

Generators rely on _____ for their functioning

• The motor principle

• Electromagnetic induction

• Alternating current

• Chemical energy

A renewable resource is one that

• Regenerates instantly

• Regenerates over millions of years

• Regenerates in a human relevant time

• Does not regenerate

How is a DC motor or generator different than an AC one?

• AC generators don't have permanent magnets

• AC generators use slip rings instead of a commutator ring

• AC generators use a commutator ring instead of slip rings

• AC generators change their rotation direction each cycle

What is the function of slip rings?

• Alternate contacts as the coil rotates

• Maintain contacts as the coil rotates

What happens when a single loop generator is at 90 degrees to the external field?

• Max current is produced

• No current is produced

• A moderate current is produced

What happens when a single loop generator is at 270 degrees to the external field?

• Max current is produced

• No current is produced

• A moderate current is produced

Which of the following would not increase the output of a generator?

• Use stronger magnets

• Use a coiled conductor

• Rotate the coil slower

• Use a soft-iron armature

What law allows us to determine the direction of current in a generator?

• Lenz's law

• Kirchhoff's laws

• Ohm's law

• Ampere's law

True or false: the primary and secondary coil of transformer are not electrically connected

• True

• False

If you wanted to decrease the voltage, you would use a

• Step-up transformer

• Step-down transformer

• DC-transformer

• Decrease transformer