Test - Unit 8 Electricity and Magnetism

Question 1

This exerts a force that causes other electric charges to move

Answer 1

Electrical fields

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Question 2

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 2

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

U8 C4 - electricity and magnetism

Question 3

What is the current of the circuit in the picture?

Answer 3

0.6 amps

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Question 4

The force or push that causes electric charges to move is called

Answer 4

Voltage difference

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Question 5

Which of the following objects would not be a good insulator of an electric charge?

Answer 5

Skin

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Question 6

When non-magnetic materials become attracted to magnets

Answer 6

Ferromagnetism

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Question 7

Silver has a resistance of 0.0198 ohms. What voltage would produce a current of 100 amps?

Answer 7

1.98 V

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Question 8

What is the current produced by a 9-volt battery flowing through a resistance of 0.2 ohms?

Answer 8

45 amps

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Question 9

Alexandra was preparing to go on a hike in the woods. She gathered the equipment she would need and placed it on the kitchen counter. By chance, she placed her compass near an electrical outlet. Although the compass was not moving. The compass needle turned because ___

Answer 9

The electric current in the outlet produced a magnetic field

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Question 10

This contains a piece of metal that melts if it gets too hot in order to open a circuit

Answer 10

Fuse

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Question 11

Which of the following will increase the resistance of a wire?

Answer 11

Increasing the temperature of the wire

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Question 12

A material through which electrons do not flow easily is a(n) ___

Answer 12

Insulator

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Question 13

Which of the following statements about electric charge is true?

Answer 13

Electrical forces act at a distance

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Question 14

Which circuit below contains the greatest voltage?

Answer 14

A circuit with a current of 25 amps and a resistance of 16 ohms

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Question 15

Temporary magnet made by placing a piece of iron inside a current carrying coil of wire

Answer 15

Electromagnets

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Question 16

Mr. Robinson and his class are conducting an experiment. The class needs to choose a good insulator. Which of the following could be used as an insulator?

Answer 16

Plastic plate

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Question 17

Electric charges always flow from ___ to ___ areas

Answer 17

Negative, positive

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Question 18

42. Charges can act at a distance by exerting a(n) ___ which is an example of charging by ___

Answer 18

Electric field and induction

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Question 19

43. Explain how lightning is created. Include type of electric charge transfer it is.

Answer 19

• movement of clouds senses a build up of static electricity
• when electrons build up enough it induces a positive charge on electrons
• attraction becomes so great that electrons go to earth to remove a static discharge

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Question 20

44. Explain how a battery works

Answer 20

• difference between positive and negative terminals
• when connected, this pushes current through wire due to voltage diff.
• electrons flow from negative to positive end

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Question 21

45. List the four factors that affect resistance in a circuit

Answer 21

• material
• size
• length
• temperature

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Question 22

48. List two differences between series and parallel circuits and list a real world example of each

Answer 22

Series 
-1 path
-all must work at one 
Ex. Flashlight
Parallel
-more than 1 path
-can use one part at a time 
Ex. House 

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Question 23

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

Answer 23

Fuse - a piece of metal that melts when overheated to open circuit

Circuit breaker - a piece of metal that breaks when overheated to open circuit

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Question 24

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

Answer 24

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

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Question 25

53. Explain ferromagnetism. Make sure to include what is happening to the electrons in the atoms

Answer 25

When nonmagnetic objects are placed in a strong enough magnetic field and become magnetic due to poles within their allgoing (all electrons orient in same direction)

U8 C4 - electricity and magnetism