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1.
Name some magnetic
substances?
answer
Iron, nickel, cobalt.
2.
What is a magnetic field?
answer
An invisible force field which
exists around a magnet.
3. How could you control the
strength of an electromagnet?
answer
•Increase the number of turns of coil
•Increase the current in the coil
•Increase the length of coil.
4.
Fill in the attached table on atomic
structure.
answer
Particle
Proton
Electron
Charge
Location
Positive
Nucleus
Negative
Nucleus
Neutron
Neutral
Orbit
around nucleus
5.
What can happen when you rub
one substance against another?
answer
Charge can build up because
electrons are transferred
6.
What is current?
answer
The movement of electrical
charge around a circuit.
7. Why can electrical conductors
conduct? Given an example of a
conductor.
answer
•They allow free moving
electrons to pass through.
• Metals are good examples of
conductors.
8.
Why can electrical insulators not
conduct? Given an example of an
insulator.
answer
•They have no free moving
charges.
• Plastic, glass and air are
good examples of insulators.
9. What is the unit of current?
answer
Amperes.
10. What is the unit of electrical
charge?
answer
•Coulombs
11. What is the current in amperes in
a circuit if you have 150 coulombs of
charge in 5 mins?
answer
Time = 5 mins = 5 X 60 secs = 300 secs.
Current = Charge / Time
I = Q/t
I = 150 / 300
I = 0.5 A.
12. Explain what potential
difference is.
answer
It is a measure of the potential
energy difference per coulomb
between two points in a circuit or
electric field
13. Give another name for
potential difference and what is its
unit..
answer
Voltage.
Measured in volts.
14. What is the voltage of a
battery?
answer
A measure of the energy
given to each unit of charge
that moves through the
battery.
15. What does D.C. mean? What
sort of sources produce this.
answer
Direct current.
Produced by batteries and solar
cells (amongst others).
16. Explain what A.C. means.
What type of source produces it.
answer
•Alternating current.
•Changes direction every fraction of a second.
•Produced by spinning generators.
17.
What type of electrical supply
voltage is mains electricity?
answer
A.C.
Voltage: 230Volts
Frequency: 50Hz
18. What are these the symbols for?
answer
Battery
Fuse
19. What are these the symbols for?
answer
Resistor
Capacitor
20. What are these the symbols
for?
answer
Variable resistor
Diode
21. What are these the symbols for?
answer
Lamp
switch