P2.5 - Magnets and Electromagnets Knowledge Test

Candidate Name:
1) What are the poles of a magnet?
2) What is the magnetic field?
3) What force is always between a magnet and a magnetic material?
4) What happens when two magnets are brought close together?
5) What does the strength of the magnetic field depend on and where is it the strongest?
6) What happens when two like poles are brought together?
7) What affects the direction of the magnetic field?
8) What happens when two unlike poles are brought together?
9) What direction does the magnetic field line go in?
10) What type of force are attraction and repulsion between magnetic poles examples of?
11) What causes a magnetic compass to follow the direction of the Earth's magnetic field?
12) What is a permanent magnet?
13) How can a plotting compass be used to plot the magnetic field pattern of a magnet?
14) What is an induced magnet?
15) What force does induced magnetism always cause?
16) Why does a compass point North?
17) What happens to an induced magnet when it's removed from the magnetic field?
18) How do the poles of the magnets interact?
19) What is the difference between permanent and induced magnets
20) What happens when a current flows through a conducting wire?
21) What does the strength of the magnetic field depends on?
22) How does shaping a wire into a solenoid affect strength of the magnetic field?
23) What is the magnetic field like inside a solenoid?
24) What is the shape of the magnetic field around a solenoid?
25) How does adding an iron core affect the magnetic field?
26) What is an electromagnet?
27) Describe how the magnetic effect of a current can be demonstrated
28) What does the magnetic field around a straight wire look like?
29) How does a solenoid arrangement increase the magnetic effect of the current?
30) (Physics only)
31) (HT only) What is meant by the motor effect?
32) What factors affect the size of the forces on the conductor?
33) How is magnetic flux density calculated? Include SI units.
34) What is the basis of an electric motor?
35) How does the force on a conductor in a magnetic field causes the rotation of the coil in an electric motor?
36) (Physics only) How do loudspeakers and headphones use the motor effect?
37) (Physics only) How do moving coil loudspeakers and headphones work?
38) (Physics only) How are potential differences induced across the ends of conductors?
39) (Physics only) What is the generator effect?
40) (Physics only) What effect does an induced current have?
41) (Physics only) What factors affect the size of the induced potential difference or induced current?
42) (Physics only) What are the principles of the generator effect?
43) (Physics only) How does the generator effect generate A.C in an alternator? What factors can affect the current in an alternator?
44) (Physics only) How does the generator effect generate D.C in an dynamo?
45) (Physics only) What would the graph showing potential difference generated in the coil against time look like?
46) (Physics only) What do microphones convert into variations in current in electrical
47) (Physics only) Explain how a moving-coil microphone works?
48) (Physics only) How does the equation linking the pds and number of turns in the two coils of a transformer link to the to the currents and the power transfer involved. Relate these to the advantages of power transmission at high potential difference.
49) (Physics only) What is the basic structure of a transformer?
50) (Physics only) Which metal is used for the core in transformers?
51) (Physics only) The ratio of the potential differences across the primary and secondary coils of a transformer (Vp and Vs) depends upon the ratio of what?
52) (Physics only) In a step-up transformer which has the greatest potential difference, primary (Vp) or secondary (Vs) coils?
53) (Physics only) In a step-down transformer which has the greatest potential difference, primary (Vp) or secondary (Vs) coils?
54) (Physics only) What would the relationship be between total power input and output in a transformer if it were 100% efficient?
55) (Physics only) Vp x Ip = the ______ _______ (primary coil). power input Vs x Is = the _______ ______ (secondary coil)power output
56) (Physics only)Explain how the effect of an alternating current induces a current in another transformer.
57) (Physics only) How does the ratio of the potential differences across the two coils depends on the ratio of the number of turns on each?
58) (Physics only) What calculation liks power, current and voltage?
59) How do the Big Ideas link to this topic?

a) Forces:

b) Particles:

c) Energy:

d) Cells: