Download Electricity Study Guide What kinds of charges repel each other

Electricity Study Guide
1. What kinds of charges repel each other? Give examples.
Like charges repel. These are positives and positives or negatives and negatives
2. What kinds of charges attract each other? Give examples.
Opposite charges attract. These are positive and negative.
3. What does the law of electric charges state?
The law of electric charges states that objects with the same charge will repel each other and objects
with opposite charges will attract each other.
4. Objects become charged by
a. Friction—passing charges back by surfaces moving past each other
b. Induction—passing charges by bring a charged object near an uncharged object
c. Conduction—passing charges by touching a charged object to an uncharged object.
d. All of the above
5. What does it mean if an object has become negatively charged?
It means that the electrons moved from one object to gather on another object. This creates one object
with more electrons (negatives) and an object with less electrons (positive).
6. Why do you feel a shock when you get out of your seat in science?
a. Because you’re a conductor
b. Because the chair’s a conductor
c. Because of static electricity
d. None of the above
7. Draw a picture of a series circuit.
8. Draw a picture of a parallel circuit.
9. Why are lights off when the switch is open?
When a switch is open, the metal is not touching so there is a break in the circuit. Since there is a break,
the electrons can’t move past it to return back to the power source and the lights will not light up.
10. What happens to the lights in a series circuit when one goes out?
If one light in a series circuit goes out, all the other lights will go out, too.
11. What happens to the lights in a parallel circuit when one goes out?
If one light goes out in a parallel circuit, all the other lights should stay on.
12. Copper is an example of a
a. Insulator
b. Semiconductor
c. Conductor
d. Gas
13. Rubber is an example of a
a. Insulator
b. Semiconductor
c. Conductor
d. Metal
14. Silicon, diodes, and transistors are examples of
a. Insulators
b. Semiconductors
c. Conductors
d. Gases
15. Current is
a. The energy in the circuit
b. The rate at which electrons pass a point
c. The opposition to the flow of electrons
d. The resistance
16. Voltage is
a. The energy in the circuit
b. The rate at which electrons pass a point
c. The opposition to the flow of electrons
d. The resistance
17. Resistance is
a. The energy in the circuit
b. The rate at which the electrons pass a point
c. The opposition to the flow of electrons
d. The buildup of charges on an object.
18. Ohm’s law describes
a. The relationship between series and parallel circuits
b. The relationship between lights on and off
c. The relationship between voltage, current, and resistance
d. The relationship between an open switch and a closed switch
19. Use Ohm’s law to calculate the current in a circuit that has 5 Ω of resistance and 25 v of voltage.
I=V/R
25 v/5 Ω= 5 A
20. Calculate the resistance of a light bulb that has 4 A of current and 12 v of voltage running through it.
R=V/I
12 v/ 4 A= 3 Ω
21. Calculate the voltage of a battery that is powering a 7 Ω light bulb with a current of 3 A.
V=IR
7 Ω x 3 A= 21 v
22. A diode is a device that allows electrical current to only travel in one direction.