Motors and Generators Pracs

Question 1

what is the motor effect?

Answer 1

the observed deflection of a current carrying wire situated in an external magnetic field

Question 2

whats the method for inducing a crruent in a coiled conductor?

Answer 2

1) establish a circuit between a galvonometer and coiled conductor with connecting wires. this coil shoudl preferably be very large
2) expose the coil to the manget. observe the reading of the galv during the magnets movement near the coil
3) move the magnet in and out of the coil at various speeds. observe the direction and magnitude of the reading on the galv and also take not on which pole enters the magnet first
4) repeat step 3 with a stronger magnet. record what diff is observed in the results
5) repeat steps 3-4 with varying distance between the magnet and coil.
6) record the results of the procedure in a suitable table

Question 3

which factors affect the size of an induced current when moving a magnet in and out of a coiled conductor?

Answer 3

• size of the coil
• number of turns in the coil
• speed of the magnet in and out of the coil
• distance from the magnet to the coil
• the strength of the magnet
• resistance of the coiled conductor

Question 4

whats the method for the production of an AC current practical?

Answer 4

1) connect an AC/DC generator to an oscilloscope using alligator clips
2) produce by turning the wheel of the generator and observe the current produced via the oscilloscope. switch and observe both AC nd DC current and note any differences
3) connect a coil to the oscilloscope and pass magnet in anout of the coil. note any diff between the current producd by the generator and coil/magnet
4) connect a battery to the oscilloscope and note the current produced. suggest reasons for the differences present between each reading compared ot the battery
5) record observations in a suitable table, titling each situation

Question 5

what materials were necessary during the AC induction motor practical?

Answer 5

• bosshead and clamp
• string
• aluminium pie dish
• drill
• two magnets
• iron plate
• blue tack
• vice
• tape

Question 6

what made the pie dish spin during the AC induction motor practical?

Answer 6

the drill with the iron plate and the two magnets spins and creates a rotating magnetic field in the stator. this threads a change in flux in the conducting dish, inducing eddy currents in the dish via lenz law. this effect causes the dish to experience a force and torque via the motor effect, causing the dish to effectively ‘chase’ the rotating external b field