Download chapter 18 test

CHAPTER 18 TEST
Directions: Show work on problems. Choose correct answer when available and place next to the question
number.
Electrostatics 18:
Q = Ne
F = kQ1Q2/d2
E = F/Q
1 C = 6.25 * 1018 electrons
1 electron = 1.60 * 10-19 Coulombs (elementary charge)
k = 8.93 NM2/C2
Electrons:
mass = 9.109 389 7 * 10-31 kg
Protons:
mass = 1.672 623 1 * 10-27 kg
Neutrons:
mass = 1.674 928 6 * 10-27 kg
USE THE ABOVE DIAGRAM TO ANSWER THIS QUESTION AND THE NEXT 2 QUESTIONS.
1.
Suppose the test material is made of material that is a conductor. What charge will be transferred to
the pith ball from the rod?
A. a neutral charge
C. a negative charge
B. a positive charge
D. No charge will be transferred.
2.
If the test material is a good conductor, what will the pith ball do when the rod touches the test
material?
A. The pith ball will be repelled from the test material.
B. The pith ball will be attracted to the test material.
C. The pith ball will transfer neutral charge to the test material.
D. The pith ball will get very hot.
3.
What charge will the rod transfer to the pith ball if the test material is an insulator?
A. a positive charge C. a positive and negative charge
B. a negative charge D. No charge is transferred.
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USE THE ABOVE DIAGRAM TO ANSWER THIS QUESTION AND THE NEXT QUESTION.
4.
The rod has a positive charge. If the electroscope is charged by conduction, what charge would the
electroscope have?
A. a positive charge C. a neutral charge
B. a negative charge D. no charge
5.
The rod has a positive charge. If the rod is brought near the electroscope, what happens to the
electroscope if it is grounded?
A. Electrons move away from the electroscope.
B. Electrons move to the electroscope.
C. The electroscope loses its charge.
D. None of the above occurs.
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6.
Suppose an electroscope has a neutral charge. A negatively charged rod is brought close to the sphere
of the electroscope but does not touch it. Which of the following statements best explains what
happens?
A. The leaves of the electroscope spread out because of conduction.
B. The charges on the electroscope spread out because they have positive charges that repel each
other.
C. The leaves of the electroscope spread out because they have positive charges that repel each other.
D. The charges on the electroscope segregate, with the positive charges on the sphere and the negative
charges on the leaves.
USE THE ABOVE DIAGRAM TO ANSWER THIS QUESTION AND THE NEXT QUESTION.
7.
If the plates are parallel and close together, what is the region between the plates called?
A. an electroscope
B. a uniform electric field
C. an electric charge
D. an electrostatic generator
8.
How can the negatively charged oil drop be balanced between the two charged plates in diagram B?
A. by increasing the amount of downward electrostatic force
B. by increasing the gravitational pull on the negative charge
C. by neutralizing the particle
D. by adjusting the amount of charge on the plates
9.
Which of the diagrams above best describes the electric field between two positively charged
spheres?
A. diagram A B. diagram B C. diagram C D. diagram D
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10.
What is the Greek word for amber?
A. elektron B. atomos C. electron D. protomos
11.
Who first identified the two "electric states" of materials and gave them the names we use today?
A. Millikan B. Ohm C. Franklin D. Volta
12.
All matter is composed of small particles called
A. carbon compounds. B. nitrogen gases. C. atoms. D. gravity.
13.
Which of the following has the largest mass?
A. neutron B. proton C. electron D. elementary charge
14.
Which of the following has a negative charge?
A. neutron B. proton C. electron D. atom
15.
Which of the following has a positive charge?
A. neutron B. proton C. electron D. atom
16.
Which of the following has no charge?
A. proton B. electron C. ion D. neutron
17.
Atoms that gain extra electrons are known as
A. molecules. B. negative ions. C. positive ions. D. neutral.
18.
The Principle of Conservation of Electric Charges says that when a quantity of positive charge is
created in a closed system, an equal quantity of
A. neutral particles appears also.
B. negative charge appears also.
C. positive charge appears also.
D. negative and positive charges appears also.
19.
Most solids are classified into
A. gases or liquids.
C. electrons or protons.
B. positive or negative charges. D. insulators or conductors.
20.
Most metals are excellent
A. conductors. B. insulators. C. elementary charges. D. generators.
21.
Which of the following would be a good conductor of electrons?
A. rubber and aluminum
C. copper and aluminum
B. wood and glass
D. cork and glass
22.
When ebonite and fur are rubbed together, electrons are removed from the fur and are placed on the
ebonite rod. What is the charge on the fur now?
A. positive B. negative C. neutral D. gravitational
23.
An object charged by conduction by a charged rod will have
A. the opposite charge than the rod has C. a noncontact charge.
B. the same charge as the rod has.
D. a neutral charge.
24.
An object charged by induction by a charged rod will have
A. the opposite charge than the rod has. C. a noncontact charge.
B. the same charge as the rod has.
D. a neutral charge.
25.
Why is Earth good at grounding electrically charged objects?
A. It spins very quickly.
B. It has a large magnetic field.
C. It can receive or give up a large number of electrons without becoming appreciably charged.
D. The sun attracts electric charges.
26.
Charge distribution is more uniform over the surface of a
A. sphere. B. square. C. cone. D. pyramid.
27.
Charge distribution is more concentrated near
A. a round object. C. sharp, pointed contours in an object.
B. a sphere.
D. a cylinder.
28.
Field lines show the direction of the electric force on a small_______ test charge placed at each point
in the field.
A. negative B. positive C. neutral D. ionic
29.
Who was the first person able to determine the amount of charge found on an electron?
A. Franklin B. Millikan C. Coulomb D. Ohm
30.
In the oil drop experiment, what force acted in an upward direction to counter the weight of the oil
drops?
A. electric force
C. strong nuclear force
B. gravitational force D. weak nuclear force
31.
What is the elementary charge of an electron?
A. 1.6 x 10-19C C. 8.0 x 10-19C
B. 3.2 x 10-19C D. 9.0 x 10-19C
32.
How many electrons does 1 C of charge equal?
A. 1.6 x 10-19
C. 6.24 x 10-18
B. 1.6 x 1019
D. 6.24 x 1018
33.
Which of the following statements does NOT agree with the Law of Electric Charges?
A. Oppositely charged objects attract each other.
B. Negatively charged objects repel each other.
C. Positively and negatively charged objects repel each other.
D. Positively charged objects repel each other.
34.
Which of the following statements about atoms is NOT correct?
A. "Atom" comes from a Greek word meaning "not able to be cut."
B. The nucleus of the atom takes up most of the volume of an atom.
C. The nucleus of the atom makes up most of the mass of the atom.
D. The atom is electrically neutral.
35.
Which of the following statements is NOT correct?
A. Negatively charged solids have an excess of electrons.
B. Positively charged solids have a deficit of electrons.
C. Negatively charged solids have their normal amount of protons.
D. Protons easily move from atom to atom in a solid.
36.
What is the difference between a good conductor and a good insulator?
A. Electrons are able to move easily in a good conductor.
B. Electrons are able to move easily in a good insulator.
C. Electrons are tightly held by a good conductor.
D. Protons are able to move easily in a good insulator.
37.
Which of the following statements can explain what happens as you move across a rug and rub
electrons from the rug onto your shoes?
A. You are grounded; no charge can build up on you.
B. The rug does not have enough electrons to build up charge.
C. You are given a negative charge, while the rug is now positive.
D. Protons are rubbed from your shoes onto the rug to make it positive.
38.
Which of the following statements is true?
A. Rubbing two objects together always creates an electric charge.
B. Wool holds on to its electrons better than gold does.
C. The transfer of neutrons generates an electric charge.
D. Rubbing provides close contact for electrons to be transferred.
39.
A negatively charged rod is brought very close to a neutral pith ball. Which observation best
describes what happens next?
A. The pith ball is repelled by the rod.
B. The pith ball touches and then is repelled by the rod.
C. The pith ball comes into contact with and sticks to the rod.
D. The pith ball is first repelled by and then attracted to the rod.
40.
What design would make a good tip for an electric arc welding device?
A. a sharp, pointed tip
C. a smooth, spherical tip
B. a smooth, oval tip
D. a rough tip with lots of surface area
41.
How did Franklin give the names "positive charges" and "negative charges" to the two electric states?
A. He knew that electrons had a negative charge.
B. He assigned the names arbitrarily.
C. He knew that protons had a positive charge.
D. He knew that neutrons had a neutral charge.
42.
When doing Millikan's oil drop experiment, it is best to obtain drops with small charges. When the
electric field is turned on, should you try to find drops that are moving fast or slow?
A. Slow. The smaller the charge, the less the electric force. This results in a small terminal velocity.
B. Slow. The larger the charge, the less the electric force. This results in a small terminal velocity.
C. Fast. The larger the charge, the greater the electric force. This results in a larger terminal velocity.
D. Fast. The smaller the charge, the greater the electric force. This results in a larger terminal
velocity.
43.
Two charges, Y and Z, are separated by a distance d and exert 1N force on each other. What net force
will exist if the distance d is doubled?
A. 0.25 N B. 2N C. 0.5N D. 4N
44.
Electrons move from the cloth to the balloon. When a balloon is rubbed with a wool cloth, what
happens?
45.
Why are atoms electrically neutral?
46.
Why do the leaves on an electroscope move apart from each other?
47.
In what way can a conductor remain neutral, even when other charged objects are brought into contact
with it?
48.
Gold, when rubbed with fur, acquires excess electrons. Similarly, brass acquires electrons when it is
rubbed with fur, though brass tends to acquire fewer electrons than gold. Predict what happens when
neutral gold and neutral brass are rubbed together and then kept in contact.
49.
One aluminum sphere is supported by a conductor and another aluminum sphere is supported by an
insulator. Which sphere would have an even distribution of electric charge after being touched by a
charged ebonite rod?
50.
What property makes glass an excellent insulator?
51.
Four different colored pith balls are attached by different strings to a ring on a ring stand. The yellow
ball has been charged by induction using an ebonite rod rubbed with fur. The blue ball repels the
green ball. The red ball and the blue ball are attracted to the yellow ball. What are the charges on the
blue and green balls?
52.
What would happen if a sharp nail were attached to the sphere of a Van de Graaf generator?
53.
How many electrons are on an oil drop if that oil drop has a charge of 1.60 x 10-20C?
54.
In 20 s, an electric charge of 5.0 C passes through an automobile light bulb. How many electrons
move through the bulb in this time?
55.
Why are fabric sheets added to clothes dryers?
56.
Why can an insulator that is charged be discharged when it is passed through a flame?
57.
If you are outside during a thunderstorm and start to feel a tingling sensation, lightning may be ready
to strike near you. What is the proper action to take?
58.
Suppose you have driven in a car for a while on a cool, dry day. As you leave the car and touch the
door, you get a static shock. What may have caused this?
USE THE ABOVE DIAGRAM TO ANSWER THIS QUESTION AND THE NEXT 2 QUESTIONS.
59.
Which diagram(s) will result in the pith ball and rod repelling each other?
60.
Which diagram(s) will result in the pith ball and rod attracting each other?
61.
In which diagram are the pith ball and rod both neutral?
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USE THE FOLLOWING KEY TO ANSWER THIS QUESTION AND THE NEXT 2 QUESTIONS.
KEY: A. repel each other.
C. attract some neutral objects.
B. attract each other.
D. repel some neutral objects.
62.
Opposite electric charges
63.
Charged objects
64.
Similar electric charges
65.
Which statement best describes what happens when charged rods are brought close to a stream of
water?
A. The stream of water is attracted to both positively and negatively charged rods.
B. The stream of water is attracted only to the positive rod.
C. The stream of water is attracted only to the negative rod.
D. The stream of water is not affected by the charged rods.
66.
What happens when a negatively charged object touches a neutral object?
A. The charged object becomes neutral.
B. The neutral object becomes negative by conduction.
C. The neutral object becomes negative by induction.
D. The neutral object becomes positive by induction.
67.
What happens when you touch the ball of the electroscope with your finger?
A. Protons are removed from your finger.
B. Protons are removed from the electroscope.
C. Electrons are removed from or added to the electroscope to make it neutral.
D. The electroscope obtains a negative charge.
68.
Why isn't it easy to create an induced charge separation on an insulator?
A. Insulators are very brittle.
B. Insulators hold on to their electrons tightly so they cannot migrate.
C. Insulators are only positively charged.
D. Insulators do not have any electrons.
69.
What charge does the electroscope obtain when a charged glass rod touches it?
A. neutral B. negative C. positive D. Glass cannot hold a charge.
70
When a rod of the opposite charge is brought close to the knob of a charged metal-leaf electroscope,
what happens to the leaves?
A. The leaves come together.
B. The leaves stay the same distance apart.
C. The leaves move twice the distance apart.
D. The leaves are not affected by the charged rod.
71.
Suppose a spark jumped from an ebonite rod to a metal rod as you were trying to induce a charge.
What should you do to prevent the spark?
A. Bring the ebonite into quick contact with the metal rod.
B. Don't move the rod so close to the metal rod.
C. Clean the metal rod with water.
D. Clean the ebonite rod with soap and water.
72.
When charging by induction, why are the metal rods placed on glass beakers?
A. The beakers prevent the rods from getting hot.
B. The metal rods will not rust on the beakers.
C. The beakers are good conductors.
D. The beakers are good insulators.
73.
In using a Millikan-like technique to find the mass of a single marble, using bags filled with unknown
quantities of marbles, what must be true?
A. Each marble must have the same mass.
B. Each marble must be the same texture.
C. Each marble must be the same density.
D. Each marble must be the same volume.
74.
Which statement would be true if all the bags of marbles had an even number of marbles in them?
A. It would be hard to find the mass of the bag of marbles.
B. The mass calculated for a single marble would be twice the actual mass of one marble.
C. The bag would not be big enough.
D. The marbles could not be counted.