Module 12

Question 1

1a. define: Photon

Answer 1

a small “package” of light that acts like a particle

Question 2

1b. define: charging by conduction

Answer 2

charging an object by allowing it to come into contact with an object that already has an electrical charge

Question 3

1c. define: charging by induction

Answer 3

charging an object without direct contact between the object and a charge

Question 4

1d. define: electrical current

Answer 4

the about of charge that travels past a fixed point in an electric circuit each second

Question 5

1e. define: conventional current

Answer 5

Current that flows form the positive side of the battery to the negative side. This is the way current is drawn in circuit diagrams, even though it is wrong

Question 6

1f. define: resistance

Answer 6

the ability of a material to impede the flow of charge

Question 7

1g. define: open circut

Answer 7

A circuit that does not have a complete connection between the two sides of the power source. As a result, current does not flow.

Question 8

2. look in book on page 311, #2

Answer 8

look in book

Question 9

3. The force between the south pole of a magnet and the north pole of another magnet is measured. If the distance between the poles is increased by a factor of 3, how does the new force compare to the old one? Is the force attractive or repulsive?

Answer 9

the force is divided by 9; it is an attractive force

Question 10

4. Two charged particles are placed 10 centimeters from each other and the resulting force is measured. The charge on object #1 is then doubled and the charge on object #2 is left the same. Also, the distance between the objects is reduced to 5 centimeters. How does the new force compare to hte old force?

Answer 10

the new force is 8 times stronger than the old one

Question 11

5. What causes the electromagnetic force?

Answer 11

the exchange of photons causes the electromagnetic force

Question 12

6. Given your answer to question #5, why don’t charged particles glow?

Answer 12

charged particles do not glow because the photons they emit are not visible to you and me

Question 13

7. If you were to use a positively charged rod to charge an object by induction, what charge will the object have?

Answer 13

the object will be negatively charged

Question 14

8. If you were ti use a positively charged rod to charge an object by conduction, what charge will the object have?

Answer 14

the object will be positively charged

Question 15

9. An electrical circuit uses a large voltage but a small current. Is the energy of each electron high or low? Are there many electrons flowing through the circuit, or are there few? Is the circuit dangerous?

Answer 15

each electron has high energy; few electrons flow through the circuit; the circuit could be dangerous

Question 16

10. Under what conditions is an electrical current reasonably safe?

Answer 16

a circuit is reasonably safe when both the voltage and the current are low

Question 17

11. look in book on page 312, #11

Answer 17

look in book

Question 18

12. look in book on page 312, #12

Answer 18

conventional current assumes that electricity is the flow of positive charges

Question 19

13. You have two wires. One is long and the other is short. Other than that, they are identical. Which has more resistance?

Answer 19

the longer wire has more resistance

Question 20

14. You have two wires. One is thin and the other is thick. When the same current is run through each wire, which will get hotter?

Answer 20

the thin wire will get hotter

Question 21

15. look in book on page 312, #15

Answer 21

in circuit (b), the light bulb glows

Question 22

16. Three lights are in a circuit. When one burns out, they all go out. When the burnt-out one is replaced with a good light, the other two lights work again. Are the lights wired in a parallel circuit or a sires circuit?

Answer 22

the bulbs are wired in a series circuit

Question 23

17. If it takes a flow of charged particles to make a magnet, where is hte charged particle flow in a permanent magnet?

Answer 23

in a permanent magnet, the flow of charged particles is the motion of the electrons in its atoms

Question 24

18. Is it possible to have a permanent magnet with only a north pole?

Answer 24

this is not possible

Question 25

19. Is it possible to make a magnet from something that is not a magnet?

Answer 25

yes

Question 26

20. If a material does not respond to a magnet, what can you conclude about the atoms in that material?

Answer 26

if a material is not magnetic, its atoms cannot be aligned