Chapter 15 Electromagnets, motor effect and generator effect

Question 1

what is the method for investigating the strength of electromagnets (6)

Answer 1

1. strip insulation from both ends of wire.
2. coil half of the wire around an iron nail, leaving enough wire at each end to connect the wire.
3. Attach crocodile clips to the wire ends.
4. Secure the nail with coils in a stand
5. connect the circuit, as shown in the diagram.
6. set the power supply to zero, close the switch, and gradually increase the voltage.
7. adjust the current until the nail supports on paper clip. record the current.
   8.repeat for up to six paper clips, recording the current each time.
8. ensure the coil doesn’t overhead; turn off if necessary.
   * make sure to keep the number of turns constant and the number of paper clips shows the strength of electromagnet.

Question 1

what is a motor effect (3-4)

Answer 1

where a current carrying wire creates its own magnetic field around the wire. So then there are 2 magnetic fields, one from the permanent magnet and the current carrying wire. These two fields interact resulting in a resultant force.

Question 2

what is a motor effect on a coil of wire (3-4)

Answer 2

there is a magnetic field from the permanent magnet and a current in a wire causes a magnetic field. these 2 fields interact producing a resultant force on the wire. The current is in opposite directions in each side of the coil. So forces act in opposite directions on either side of the coil.

Question 3

What is the generator effect/AC generator (3-4)

Answer 3

The conductor is in a changing magnetic field. A permanent magnet is moving in and out the coil/ the coil is moved relative to the magnet and a potential difference is induced. (If the wire is in a closed circuit, a current flows in the wire. the magnetic field produced by the induced current opposes the field of the permanent magnet.)

Question 4

what is a solenoid

Answer 4

a loop of wire

Question 5

what is AC

Answer 5

an alternating current

Question 6

what is DC

Answer 6

direct current

Question 7

how do you know if its an DC

Answer 7

if the current flows in only one direction it is called a direct current.

Question 8

how do you know if its a AC

Answer 8

If the current constantly changes direction, it is called alternating current.

Question 9

how many volts does the UK supply and what is the frequency of the volts

Answer 9

230V with a frequency of 50Hz

Question 10

What is an alternator

Answer 10

generator producing alternating current

Question 11

What is a Dynamos

Answer 11

generator produces a direct current

Question 12

What is an induced magnet

Answer 12

a material that becomes a magnet when it is placed in a magnetic field.