Electromagnetic Effects

Alternating current differs from direct current because...

• it alternates from AC to DC

• the current alternates between 2 A and 5 A

• the resistance fluctuates back and forth.

• the current changes direction (forwards and backwards) alternatively

What is an example of an appliance that uses A.C current?

• Flash light

• Dishwasher

• Battery

• Cell Phone

What is the left hand rule used for?

• Motors

• Generators

• a.c. current

• d.c. current

What is Fleming's right-hand rule used for?

• Generators

• Motors

• a.c. current

• d.c. current

What does the electromagnetic force measure?

• Newtons

• Kg

• Amperes (Amps)

• Volts

How do you increase the turning effect of a d.c. motor?

• Increase the surface area

• Increase potential difference

• Increase the number of turns in the coil

• Increase the current

What are split ring commutators needed for?

• Decreasing the current every half turn

• Increasing the current every half turn

• Reversing the current every half turn

• Stopping the current every half turn

(delete if too much)

What does the thumb in either Fleming's left hand / right hand rule indicate?

• (Direction of) Magnetic field

• (Direction of) Force

• (Direction of) Current

(delete if too much)

What does the index finger mean in Fleming's left hand / right hand rule?

• (Direction of) Current

• (Direction of) Force

• (Direction of) Magnetic field

What does a simple A.C generator consist of?

• Slip rings connected to a flow of current

• A coil of wire rotating in a magnetic field

• Electromagnet connected to a A.C source

• None of the above