Test- Unit 8 Electricity and Magnetism

Question 1

42. Charge can act at a distance by exerting a electric force which is an example of charging by…

Answer 1

Induction

Question 2

43. Explain how lightning is created.

Answer 2

Movement of clods causes a build up of static electricity.

Question 3

48. Series- real world example

Answer 3

Flash light

Question 4

49. Find the total resistance and the current in the circuit below.

Answer 4

R=100+80+20= 200 ohms
V=60 V
I=V/R
I=60/200= 0.3 amps

Question 5

50. Find the total resistance and the voltage if the circuit has a current of 40 amps flowing through it.

Answer 5

1/r= 1/5+1/10+1/20
1/r=4/20+2/20+1/20
1/r=7/20
7r/7=20/7
R= 2.86 ohms

V=?
R=2.86 ohms
I= 40 amps
V=IR

V=114.4

Question 6

51. Explain the two ways we discussed to keep a house from overheating

Answer 6

Liffvit breaker- piece of metal that breaks when overheated to open.

Question 7

52. Describe what an electromagnets is and list the two ways to increase its strength.

Answer 7

A temporary magnet made by placing a piece of iron in a current carrying coil of wire.

Question 8

53. Explain ferromagnetism. Make sure to include what is happening to the electrons in the atoms. You may draw a picture if that helps.

Answer 8

When non magnetic objects are pieced in a string enough magnetic field and become magnetized due to poles within their atoms aligning.

Question 9

Circuit___ is the type of circuit that causes an entire string of lights to go out when one of the bulbs burn out

Answer 9

Series

Question 10

When non-magnetic materials become attracted to magnets.

Answer 10

Ferromagnetism

Question 11

Circuit___represents the way homes are usually wired.

Answer 11

Parallel

Question 12

Electric charges always flow form___ areas to___ areas.

Answer 12

Negative, positive

Question 13

Laser printers work with the use of heat and positive and negative charges. The laser etches a negative charge on spots of the printer drum in the form of text or images. The plastic ink dust is attracted to the places on the drum with this negative charge. What is the charge of the plastic ink dots themselves?

Answer 13

Positive

Question 14

In a closed circuit containing one resistor and a battery, if the voltage in the battery increases, the current going through the resistor increases. Why does this occur?

Answer 14

As the electrons are pushed more by the battery, they move faster through the circuit.