Transcript negatively charged - Henry County Schools

Electricity
&
Magnetism
Static Electricity
1. What is an electric charge?
- tiny particles that make up matter with a
charge
2. What effect do positive
and negative charges
have on one another?
- they cancel each other out
3. What does it mean to be negatively charged and
positively charged?
- negatively charged: has more charges that are
negative
- positively charged: has more charges that are
positive
4. What do you call matter that has a
balance of positive and negative charges?
-neutral; matter contains equal
numbers of positive and negative charges
5. What is one way an object becomes charged?
-by being rubbed (friction)
6. Draw the different charges.
Positive Charge Negative Charge
6. Describe what happens to charges in a chart
below.
N
P
N
P
N
P
8. What is static electricity?
- a buildup of charges in one place.
Example: rubbing socks against
carpet then touching a metal
doorknob
9. What causes the shock when you touch a metal
doorknob after walking across a carpet?
- a charge jumping/transferring
from you to the doorknob
10. Why do you think most objects don’t attract
and repel one another?
-the objects are neutral
Electric Forces
11. What is an electric force?
- the push or pull between two difference objects
12. What is an electric field?
-the area around the two electric charges
13. Draw a picture of an electrical field /electrical
force.
Electrical Field
Electrical Force
Circuits
14. Describe an electric current.
-a flow of electric charges
15. Explain an electric circuit.
-a closed path that current
flows through; has
a battery and wire
16. Draw a picture of an electrical current.
***Label the parts***
17. How is current electricity different from static
electricity?
-in currentl electricity, charges keep moving
around a circuit; in static electricity, charges
separate but not
continually move
18. Which is more useful to people?
- current electricity is more useful
to people because it can be controlled
Series/Parallel Circuit
19. Describe a series circuit.
-it has only one path for its current to follow;
you can add more than one device; when path
is broken, devices will stop working
20. Draw a series circuit.
Draw a Series Circuit
***Label the parts***
21. Can a series circuit have more than one device?
What happens if you remove a device in a series
circuit?
-yes; all the devices stop working b/c the circuit is
not longer complete and current cant flow.
22. Why aren’t all lamps and divices in homes
wired in a series circuit?
-if one goes out or is unplugged, they all go
out
23. When you press the switch on a lamp, the light
goes off or on. What does the switch do to make
this happen?
-completes the circuit to make the lamp light
work; it opens the circuit to make the lamp
turn off
24. Describe a parallel circuit.
- has more than one path for the current to
follow; the more added to device, the
weaker current will be
Example: Schools, homes, and business
Draw a Parallel Circuit
***Label the parts***
25. How is a parallel circuit different from a series
circuit?
-a parallel circuit has more than one path that
the current can follow; if one path is open or
damaged, electricity can flow along the other
path; a series circuit has only one path that
current can follow
26. Why are devices in homes and schools plugged
into sockets rather than being all wired together?
-so they can be turned on or off separately
26. In a parallel circuit, what effect does removing one
device have on the other device?
- it has no effect; the other devices still works
Resistance
27. What is resistance?
- how much a material
opposes the flow of a
current
28. Compare the resistance of thick and thin wires?
-thick wires have lower resistance than thin wires
29. Describe a short circuit.
-a current takes a shortcut where it isn’t
wanted
30. What effect does adding devices have on the
resistance of a series circuit?
-adding devices increases the total resistance
of the circuit
Conductors & Insulators
31. Describe conductor.
- is a material in which
charges move easily through
32. What makes a good conductor?
-metals; copper; silver; salt water;
iron; gold; aluminum; steel
33. Describe an insulator.
- material that resists the flow or electricity
34. What makes a good insulator?
- most plastics; glass; cloth; sand; rubber;
wood; dry air
Electromagnets
35. What is an electromagnet?
- a temporary magnet that has
coils of current running wire
around an iron core (nail).
36. How can you make the magnetic field around a
current carrying coil of wire stronger?
-wrap the coil around an iron core
37. How does the field around a current carrying wire
compare to the magnetic filed around a bar magnet?
- field lines around a bar magnet loop out from
the north seeking end of the magnet to the south
seeking end; the field lines around a current
carrying wire circle the wire
38. What happens to an electromagnet when you
remove the battery or power supply?
-the electromagnet will stop working
39. Which is an advantage of a magnet that you
can turn off and on?
a) they can be turned on and off by turning
the current on and off.
b) they can be made stronger or weaker by
either changing the strength of the battery or
by changing the number of wire loops
c) the direction of the field can be changed
(switching the poles) by switching the ends
attached to the battery
40. How can electricity be used to make a
magnet?
- a wire that carries an electric current has a
magnetic field; if you wrap the wire around a
nail, the nail become a magnet; the more
coils, the stronger the nail.
41. What is the effect of using two batteries
instead of one?
- the electromagnet get stronger.
42. Difference between electromagnet and bar
magnet?
-electromagnet is temporary and bar magnet is
permanent.