Download Ch07_Clicker_Questions - Saint Leo University Faculty

Chapter 7 Clickers
Conceptual
Integrated Science
Second Edition
Electricity and
Magnetism
© 2013 Pearson Education, Inc.
Which of these particles has an electrical charge?
a)
b)
c)
d)
Proton.
Electron.
Ion.
All of the above.
© 2013 Pearson Education, Inc.
Which of these particles has an electrical charge?
a)
b)
c)
d)
Proton.
Electron.
Ion.
All of the above.
Explanation:
An ion, by definition, is a charged atom—one with an
extra electron(s) or deficient in one or more electrons.
© 2013 Pearson Education, Inc.
Which is the predominant carrier of charge in
copper wire?
a)
b)
c)
d)
Proton.
Electron.
Ion.
All of the above.
© 2013 Pearson Education, Inc.
Which is the predominant carrier of charge in
copper wire?
a)
b)
c)
d)
Proton.
Electron.
Ion.
All of the above.
© 2013 Pearson Education, Inc.
If a neutral atom has 22 protons in its nucleus, the
number of surrounding electrons is
a)
b)
c)
d)
less than 22.
22.
more than 22.
sometimes all of the above in a neutral atom.
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If a neutral atom has 22 protons in its nucleus, the
number of surrounding electrons is
a)
b)
c)
d)
less than 22.
22.
more than 22.
sometimes all of the above in a neutral atom.
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When we say charge is conserved, we mean that
charge can
a)
b)
c)
d)
be saved, like money in a bank.
only be transferred from one place to another.
take equivalent forms.
be created or destroyed, as in nuclear reactions.
© 2013 Pearson Education, Inc.
When we say charge is conserved, we mean that
charge can
a)
b)
c)
d)
be saved, like money in a bank.
only be transferred from one place to another.
take equivalent forms.
be created or destroyed, as in nuclear reactions.
Explanation:
Electric charge cannot be created or destroyed. It can
only be transferred.
© 2013 Pearson Education, Inc.
According to Coulomb's law, a pair of particles
that are placed twice as close to each other will
experience forces that are
a)
b)
c)
d)
twice as strong.
four times as strong.
half as strong.
one-quarter as strong.
© 2013 Pearson Education, Inc.
According to Coulomb's law, a pair of particles
that are placed twice as close to each other will
experience forces that are
a)
b)
c)
d)
twice as strong.
four times as strong.
half as strong.
one-quarter as strong.
Explanation:
Coulomb's law is an inverse-square law.
© 2013 Pearson Education, Inc.
According to Coulomb's law, doubling both
charges of a pair of particles will result in a force
between them that is
a)
b)
c)
d)
twice as strong.
four times as strong.
half as strong.
one-quarter as strong.
© 2013 Pearson Education, Inc.
According to Coulomb's law, doubling both
charges of a pair of particles will result in a force
between them that is
a)
b)
c)
d)
twice as strong.
four times as strong.
half as strong.
one-quarter as strong.
© 2013 Pearson Education, Inc.
When a negatively charged balloon is placed
against a nonconducting wall, negative charges in
the wall are
a) attracted to the balloon.
b) repelled from the balloon.
c) too bound to positive charges in the wall to have
any effect.
d) neutralized.
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When a negatively charged balloon is placed
against a nonconducting wall, negative charges in
the wall are
a) attracted to the balloon.
b) repelled from the balloon.
c) too bound to positive charges
in the wall to have any effect.
a) neutralized.
Explanation:
The negative balloon repels negative charge in the wall
And attracts positive charge. Charges of atoms and
molecules are therefore nudged apart. This condition of
charge separation is called polarization.
© 2013 Pearson Education, Inc.
The strength of an electric field is measured by
the force
a)
b)
c)
d)
exerted on a charge in the field.
between electric field lines.
between oppositely charged parallel plates.
all of the above.
© 2013 Pearson Education, Inc.
The strength of an electric field is measured by
the force
a)
b)
c)
d)
exerted on a charge in the field.
between electric field lines.
between oppositely charged parallel plates.
all of the above.
© 2013 Pearson Education, Inc.
The direction of an electric field, by convention, is
the direction of force that the field would exert on
a)
b)
c)
d)
an electron.
a proton.
an atom.
all of the above.
© 2013 Pearson Education, Inc.
The direction of an electric field, by convention, is
the direction of force that the field would exert on
a)
b)
c)
d)
an electron.
a proton.
an atom.
all of the above.
© 2013 Pearson Education, Inc.
When you do work on an electrically charged
particle, you change the particle's
a)
b)
c)
d)
charge.
potential energy.
capacitance.
power.
© 2013 Pearson Education, Inc.
When you do work on an electrically charged
particle, you change the particle's
a)
b)
c)
d)
charge.
potential energy.
capacitance.
power.
Comment:
Recall the work–energy theorem in Chapter 3.
© 2013 Pearson Education, Inc.
When you increase the potential energy of a
charged particle, you increase its ability to
a)
b)
c)
d)
do work.
charge other particles.
conduct.
transform to heat.
© 2013 Pearson Education, Inc.
When you increase the potential energy of a
charged particle, you increase its ability to
a)
b)
c)
d)
do work.
charge other particles.
conduct.
transform to heat.
Comment:
Recall from Chapter 3 that the potential energy
acquired by something equals the work done on it.
© 2013 Pearson Education, Inc.
Electric potential, measured in volts, is a ratio of
a)
b)
c)
d)
charge to the square of the separation distance.
current to resistance.
energy to charge.
power to current.
© 2013 Pearson Education, Inc.
Electric potential, measured in volts, is a ratio of
a)
b)
c)
d)
charge to the square of the separation distance.
current to resistance.
energy to charge.
power to current.
© 2013 Pearson Education, Inc.
A party balloon may be charged to thousands of
volts. The charged balloon isn't dangerous
because it carries relatively little
a)
b)
c)
d)
current.
energy.
capacitance.
resistance.
© 2013 Pearson Education, Inc.
A party balloon may be charged to thousands of
volts. The charged balloon isn't dangerous
because it carries relatively little
a)
b)
c)
d)
current.
energy.
capacitance.
resistance.
© 2013 Pearson Education, Inc.
A coulomb of charge that passes through a 12-volt
battery is given
a)
b)
c)
d)
12 joules.
12 amperes.
12 ohms.
12 watts.
© 2013 Pearson Education, Inc.
A coulomb of charge that passes through a 12-volt
battery is given
a)
b)
c)
d)
12 joules.
12 amperes.
12 ohms.
12 watts.
Explanation:
Voltage = energy/charge; (12 V)/(1 C) = 12 J/C.
© 2013 Pearson Education, Inc.
Which statement is correct?
a)
b)
c)
d)
Voltage flows in a circuit.
Charge flows in a circuit.
Current causes voltage.
All the above are correct.
© 2013 Pearson Education, Inc.
Which statement is correct?
a)
b)
c)
d)
Voltage flows in a circuit.
Charge flows in a circuit.
Current causes voltage.
All the above are correct.
Explanation:
Voltage is established across a circuit, not through it.
Also, voltage causes current, and not the other way
around.
© 2013 Pearson Education, Inc.
A 10-ohm resistor carries 10 amperes. The
voltage across the resistor is
a)
b)
c)
d)
zero.
more than zero but less than 10 V.
10 V.
more than 10 V.
© 2013 Pearson Education, Inc.
A 10-ohm resistor carries 10 amperes. The
voltage across the resistor is
a)
b)
c)
d)
zero.
more than zero but less than 10 V.
10 V.
more than 10 V.
Explanation:
The voltage, in accord with Ohm's law, is 100 V, much
greater than 10 V.
© 2013 Pearson Education, Inc.
A 10-ohm resistor is connected to a 120-volt
power supply. The current in the resistor is
a)
b)
c)
d)
1 A.
10 A.
12 A.
120 A.
© 2013 Pearson Education, Inc.
A 10-ohm resistor is connected to a 120-volt
power supply. The current in the resistor is
a)
b)
c)
d)
1 A.
10 A.
12 A.
120 A.
Explanation:
By Ohm's law, current = voltage/resistance = 120 V/10
ohm = 12 A.
© 2013 Pearson Education, Inc.
A major difference between DC and AC in circuits
is the
a)
b)
c)
d)
voltage associated with each.
timing associated with each.
way charges flow.
way circuits are wired.
© 2013 Pearson Education, Inc.
A major difference between DC and AC in circuits
is the
a)
b)
c)
d)
voltage associated with each.
timing associated with each.
way charges flow.
way circuits are wired.
Explanation:
In a DC circuit, charge flows in one direction; in AC,
charge flows to and fro, alternating direction.
© 2013 Pearson Education, Inc.
A 120-volt line carries 20 amperes. The power
expended is
a)
b)
c)
d)
6 watts.
20 watts.
120 watts.
2400 watts.
© 2013 Pearson Education, Inc.
A 120-volt line carries 20 amperes. The power
expended is
a)
b)
c)
d)
6 watts.
20 watts.
120 watts.
2400 watts.
Explanation:
Power = voltage  current.
© 2013 Pearson Education, Inc.
How much current is in a 120-volt line at 1200
watts?
a)
b)
c)
d)
6 amperes.
10 amperes.
120 amperes.
240 amperes.
© 2013 Pearson Education, Inc.
How much current is in a 120-volt line at 1200
watts?
a)
b)
c)
d)
6 amperes.
10 amperes.
120 amperes.
240 amperes.
Explanation:
From Power = voltage  current, current = power/voltage
= 1200 W/120 V = 10 A.
© 2013 Pearson Education, Inc.
What is the power rating of a lamp connected to a
12-V source when it carries 1.5 A?
a)
b)
c)
d)
8 W.
12 W.
18 W.
None of the above.
© 2013 Pearson Education, Inc.
What is the power rating of a lamp connected to a
12-V source when it carries 1.5 A?
a)
b)
c)
d)
8 W.
12 W.
18 W.
None of the above.
Explanation:
Power = voltage  current = 12 V  1.5 A = 18 W.
© 2013 Pearson Education, Inc.
Iron paper clips are strongly attracted to
a)
b)
c)
d)
the north pole of a magnet.
the south pole of a magnet.
either the north or south pole of a magnet.
none of the above.
© 2013 Pearson Education, Inc.
Iron paper clips are strongly attracted to
a)
b)
c)
d)
the north pole of a magnet.
the south pole of a magnet.
either the north or south pole of a magnet.
none of the above.
Explanation:
Magnetic domains in the clips are induced into
alignment in much the same way that electric charges
are induced when polarized.
© 2013 Pearson Education, Inc.
Moving electric charged particles can interact with
a)
b)
c)
d)
an electric field.
a magnetic field.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
Moving electric charged particles can interact with
a)
b)
c)
d)
an electric field.
a magnetic field.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
When a magnetized compass is placed in a
magnetic field, it aligns with the field because of
a) attracting forces between the compass and the
field.
b) torques on the magnet.
c) magnetic domains in the compass needle.
d) all of the above.
© 2013 Pearson Education, Inc.
When a magnetized compass is placed in a
magnetic field, it aligns with the field because of
a) attracting forces between the compass and the
field.
b) torques on the magnet.
c) magnetic domains in the compass needle.
d) all of the above.
© 2013 Pearson Education, Inc.
Surrounding moving electric charges are
a)
b)
c)
d)
electric fields.
magnetic fields.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
Surrounding moving electric charges are
a)
b)
c)
d)
electric fields.
magnetic fields.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
A magnetic force cannot act on an electron when
it
a)
b)
c)
d)
is at rest.
moves parallel to magnetic field lines.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
A magnetic force cannot act on an electron when
it
a)
b)
c)
d)
is at rest.
moves parallel to magnetic field lines.
both of the above.
neither of the above.
Explanation:
A force is exerted on charged particles only when they
move at an angle to magnetic field lines. The force is
greatest when motion is at right angles to the magnetic
field, and it is zero when motion is parallel to the field.
© 2013 Pearson Education, Inc.
The fact that a force is exerted on a currentcarrying wire in a magnetic field underlies
a)
b)
c)
d)
motors.
electric meters.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
The fact that a force is exerted on a currentcarrying wire in a magnetic field underlies
a)
b)
c)
d)
motors.
electric meters.
both of the above.
neither of the above.
© 2013 Pearson Education, Inc.
A motor and a generator are
a)
b)
c)
d)
similar devices.
very different devices with different applications.
forms of transformers.
energy sources.
© 2013 Pearson Education, Inc.
A motor and a generator are
a)
b)
c)
d)
similar devices.
very different devices with different applications.
forms of transformers.
energy sources.
Explanation:
The main difference in a motor and generator is
energy input and output, which are opposite for each.
© 2013 Pearson Education, Inc.
A voltage will be induced in a wire loop when the
magnetic field within that loop
a)
b)
c)
d)
changes.
aligns with the electric field.
is at right angles to the electric field.
converts to magnetic energy.
© 2013 Pearson Education, Inc.
A voltage will be induced in a wire loop when the
magnetic field within that loop
a)
b)
c)
d)
changes.
aligns with the electric field.
is at right angles to the electric field.
converts to magnetic energy.
© 2013 Pearson Education, Inc.
An electric field is induced in any region of space
in which
a) a magnetic field changes with time.
b) a magnetic field's orientation is at right angles to
the electric field.
c) the accompanying electric field undergoes changes
in time.
d) all of the above.
© 2013 Pearson Education, Inc.
An electric field is induced in any region of space
in which
a) a magnetic field changes with time.
b) a magnetic field's orientation is at right angles to
the electric field.
c) the accompanying electric field undergoes changes
in time.
d) all of the above.
Comment:
Quite wonderfully, changing electric and magnetic
fields produce light!
© 2013 Pearson Education, Inc.