The Motor Effect

Question 1

Flemming’s left hand rule (FBI rule)

Answer 1

Thumb - F/ force on conductor
First finger - B/ magnetic field
Middle finger - I/ conventional current

Question 2

What is magnetic flux density measured in?

Answer 2

Teslas (T)

Question 3

Magnetic flux density equation

Answer 3

F (N) = B (T) x I (A) x L (m)

Question 4

If the lines of magnetic flux are closer together…

Answer 4

The magnetic flux density has increased

Question 5

The motor effect

Answer 5

When a conductor carrying a current is placed into a magnetic field, the conductor and the other magnet(s) producing the field will exert a force on one another (unless conductor is parallel to the field lines)

Question 6

In the electric motor, how can direction of rotation be reversed?

Answer 6

-reversing the direction of the magnetic field
-reversing the current direction

Question 7

Is the electric motor AC or DC?

Answer 7

DC

Question 8

Split-ring commutator

Answer 8

Rotates the coil, between the carbon brushes. Each time the coil passes the vertical position, each end of the split ring commutator connected to the rotating side of the coil will be connected to the opposite end of the battery. This reverses the direction in which current flows around the coil. This reverses the direction of the force exerted on each side of the coil, in turn, causing it to rotate

Question 9

How do loudspeakers work?

Answer 9

When a current flows through the coil, both the coil and the speaker experience a force. When the direction of the current through the coil reverses, so too does the direction of the force exerted on it and the speaker cone, suppling an alternating electrical input signal to the speaker, causing the cone to vibrate, producing a sound wave