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physics exam 2
multiple choice
46
Physics
Undergraduate 3
03/30/2014

Additional Physics Flashcards

 


 

Cards

Term

 Which of the following is not a vector?

A) electric force

B) electric field

C) electric potentia;

D) electric line of force

Definition
C) electric potentia
Term

 One joule per coulomb is a

A) newton.

B) volt.

C) electron-volt.

D) farad.

Definition
B) volt
Term

 Two identical aluminum objects are insulated from their surroundings. Object A has a net

charge of excess electrons. Object B is grounded. Which object is at a higher potential?

A) A

B) B

C) Both are at the same potential.

D) cannot be determined without more information

Definition
B) Object B, the grounded object, has a higher potential.
Term

For a proton moving in the direction of the electric field

A) its potential energy increases and its electric potential decreases.

B) its potential energy decreases and its electric potential increases.

C) its potential energy increases and its electric potential increases.

D) its potential energy decreases and its electric potential decreases.

Definition
D) its potential energy decreases and its electric potential decreases.
Term

For an electron moving in a direction opposite to the electric field

A) its potential energy increases and its electric potential decreases.

B) its potential energy decreases and its electric potential increases.

C) its potential energy increases and its electric potential increases.

D) its potential energy decreases and its electric potential decreases

Definition
B) it's potential energy decreases and its electric potential increases
Term

Several electrons are placed on a hollow conducting sphere. They

A) clump together on the sphere's outer surface.

B) clump together on the sphere's inner surface.

C) become uniformly distributed on the sphere's outer surface.

D) become uniformly distributed on the sphere's inner surface.

Definition
C) become uniformly distributed on the sphere's outer surface.
Term

A small charged ball is accelerated from rest to a speed v by a 500 V potential difference. If the

potential difference is changed to 2000 V, what will the new speed of the ball be?

A) v

B) 2v

C) 4v

D) 16v

Definition
B) 2v
Term

A surface on which all points are at the same potential is referred to as

A) a constant electric force surface.

B) a constant electric field surface.

C) an equipotential surface.

D) an equivoltage surface.

Definition
C) an equipotential surface
Term

A negative charge is moved from point A to point B along an equipotential surface.

A) The negative charge performs work in moving from point A to point B.

B) Work is required to move the negative charge from point A to point B.

C) Work is both required and performed in moving the negative charge from point A to

point B.

D) No work is required to move the negative charge from point A to point B.

Definition
D) no work is required to move the negative charge from point A to point B
Term

An equipotential surface must be

A) parallel to the electric field at any point.

B) perpendicular to the electric field at any point.

Definition
B) an equipotential surface must be perpendicular to the electric field at any point.
Term

The energy acquired by a particle carrying a charge equal to that on the electron as a result of

moving through a potential difference of one volt is referred to as

A) a joule.

B) an electron-volt.

C) a proton-volt.

D) a coulomb.

Definition
B) an electron-volt
Term

The electron-volt is a unit of

A) voltage.

B) current.

C) power.

D) energy.

Definition
D) the electron-volt is a unit of energy
Term

One electron-volt corresponds to

A) 8.0 * 10-20 J.

B) 1.6 * 10-19 J.

C) 9.5 * 10-17 J.

D) 1.9 * 10-16 J

Definition
B)
Term

The absolute potential at a distance of 2.0 m from a positive point charge is 100 V. What is the

absolute potential 4.0 m away from the same point charge?

A) 25 V

B) 50 V

C) 200 V

D) 400 V

Definition
B) 50 V
Term

The absolute potential at the center of a square is 3.0 V when a charge of +Q is located at one of

the square's corners. What is the absolute potential at the square's center when a second

charge of -Q is placed at one of the remaining corners?

A) zero

B) 3.0 V

C) 6.0 V

D) 9.0 V

Definition
A) zero
Term

 Electric dipoles always consist of two charges that are

A) equal in magnitude; opposite in sign.

B) equal in magnitude; both are negative.

C) equal in magnitude; both are positive.

D) unequal in magnitude; opposite in sign.

Definition
A) equal in magnitude; opposite in sign.
Term

 One coulomb per volt is a

A) joule.

B) electron-volt.

C) farad.

D) watt.

Definition
C) farad
Term

Two parallel-plate capacitors are identical in every respect except that one has twice the plate

area of the other. If the smaller capacitor has capacitance C, the larger one has capacitance

A) C/2.

B) C.

C) 2C.

D) 4C.

Definition
C) 2C
Term

A parallel-plate capacitor has a capacitance of C. If the area of the plates is doubled and the

distance between the plates is halved, what is the new capacitance?

A) C/4

B) C/2

C) 2C

D) 4C

Definition
D) 4C
Term

A battery charges a parallel-plate capacitor fully and then is removed. The plates are

immediately pulled apart. (With the battery disconnected, the amount of charge on the plates

remains constant.) What happens to the potential difference between the plates as they are

being separated?

A) It increases.

B) It decreases.

C) It remains constant.

D) cannot be determined from the information given

Definition
A) it increases
Term

 If the electric field between the plates of a given capacitor is weakened, the capacitance of that

capacitor

A) increases.

B) decreases.

C) does not change.

D) cannot be determined from the information given

Definition
C) does not change
Term

 The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as

they are pulled apart. During this process, the amount of charge on the plates must

A) increase.

B) decrease.

C) remain constant.

D) either increase or decrease. There is no way to tell from the information given.

Definition
B) decrease
Term

The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as

they are pulled apart. What happens to the strength of the electric field during this process?

A) It increases.

B) It decreases.

C) It remains constant.

D) cannot be determined from the information given

Definition
B) it decreases
Term
3 reasons for adding dielectric material between the plates of a capacitor
Definition

1. dielectrics don't break down as fast as air, so higher voltage can be applied without letting charge flow through the gap

2. can get the plates closer without touching - increased capacitance

3. increases the capacitance

Term

 A dielectric material such as paper is placed between the plates of a capacitor holding a fixed

charge. What happens to the electric field between the plates?

A) no change

B) becomes stronger

C) becomes weaker

D) reduces to zero

Definition
C) becomes weaker
Term

A parallel-plate capacitor is connected to a battery and becomes fully charged. The capacitor

is then disconnected, and the separation between the plates is increased in such a way that no

charge leaks off. The energy stored in this capacitor has

A) increased.

B) decreased.

C) not changed.

D) become zero

Definition
a) increased
Term

Doubling the capacitance of a capacitor holding a constant charge causes the energy stored in

that capacitor to

A) quadruple.

B) double.

C) decrease to one half.

D) decrease to one fourth.

Definition
D) decrease to 1/4
Term

A car battery

A) has an emf of 6 V consisting of one 6-V cell.

B) has an emf of 6 V consisting of three 2-V cells connected in series.

C) has an emf of 6 V consisting of three 2-V cells connected in parallel.

D) has an emf of 12 V consisting of six 2-V cells connected in series.

Definition
D) a car battery has an emf of 12 V consisting of six 2-V cells connected in series
Term

The resistivity of most common metals

A) remains constant over wide temperature ranges.

B) increases as the temperature increases.

C) decreases as the temperature increases.

D) varies randomly as the temperature increases.

Definition
B) the resistivity of most metals increases as the temperature increases
Term

 Negative temperature coefficients of resistivity

A) do not exist.

B) exist in conductors.

C) exist in semiconductors.

D) exist in superconductors.

Definition
C) exist in semiconductors
Term

You obtain a 100-W light bulb and a 50-W light bulb. Instead of connecting them in the

normal way, you devise a circuit that places them in series across normal household voltage.

Which statement is correct?

A) Both bulbs glow at the same reduced brightness.

B) Both bulbs glow at the same increased brightness.

C) The 100-W bulb glows brighter than the 50-W bulb.

D) The 50-W bulb glows more brightly than the 100-W bulb.

Definition
D) The 50-W bulb glows more brightly than the 100-W bulb.
Term

As more resistors are added in series to a constant voltage source, the power supplied by the

source

A) increases.

B) decreases.

C) does not change.

D) increases for a time and then starts to decrease.

 

Definition
B) As more resistors are added to a constant voltage source, the power supplied by the source decreases.
Term

When two or more resistors are connected in parallel to a battery,

A) the voltage across each resistor is the same.

B) the total current flowing from the battery equals the sum of the currents flowing through

each resistor.

C) the equivalent resistance of the combination is less than the resistance of any one of the

resistors.

D) all of the given answers

Definition

D) all of the given answers.

 

- the voltage across each resistor is the same.

- the total current flowing from the battery equals the sum of the currents flowing through each resistor.

- the equivalent resistance of the combination is less than the resistance of any one of the resistors. 

Term

When resistors are connected in parallel, we can be certain that

A) the same current flows in each one.

B) the potential difference across each is the same.

C) the power dissipated in each is the same.

D) their equivalent resistance is greater than the resistance of any one of the individual

resistances.

 

Definition
B) the potential difference across each is the same.
Term

Three identical resistors are connected in parallel to a 12-V battery. What is the voltage of any

one of the resistors?

A) 36 V

B) 12 V

C) 4 V

D) zero

Definition
B) 12 v.
Term

The lamps in a string of Christmas tree lights are connected in parallel. What happens if one

lamp burns out? (Assume negligible resistance in the wires leading to the lamps.)

A) The brightness of the lamps will not change appreciably.

B) The other lamps get brighter equally.

C) The other lamps get brighter, but some get brighter than others.

D) The other lamps get dimmer equally.

E) The other lamps get dimmer, but some get dimmer than others.

Definition
A) the brightness fo the lamps will not change appreciably.
Term

If you connect two identical storage batteries together in parallel, and place them in a circuit,

the combination will provide

A) twice the voltage and twice the total charge that one battery would.

B) twice the voltage and the same total charge that one battery would.

C) the same voltage and twice the total charge that one battery would.

D) half the voltage and half the total charge that one battery would.

Definition
C) the same voltage, twice the total charge.
Term

When two or more capacitors are connected in series to a battery,

A) the total voltage across the combination is the algebraic sum of the voltages across the

individual capacitors.

B) each capacitor carries the same amount of charge.

C) the equivalent capacitance of the combination is less than the capacitance of any of the

capacitors.

D) all of the given answers

Definition
D
Term

Three identical capacitors are connected in series to a battery. If a total charge of Q flows from

the battery, how much charge does each capacitor carry?

A) 3Q

B) Q

C) Q/3

D) Q/9

Definition
B) Q
Term

When two or more capacitors are connected in parallel to a battery,

A) the voltage across each capacitor is the same.

B) each capacitor carries the same amount of charge.

C) the equivalent capacitance of the combination is less than the capacitance of any one of the

capacitors.

D) all of the given answers

Definition
A
Term

 Three identical capacitors are connected in parallel to a battery. If a total charge of Q flows

from the battery, how much charge does each capacitor carry?

A) 3Q

B) Q

C) Q/3

D) Q/9

Definition
C) Q/3
Term

What is the unit for the quantity RC?

A) ohms

B) volt-ampere/ohm

C) seconds

D) meters

Definition
C) seconds
Term

A resistor and a capacitor are connected in series to an ideal battery of constant terminal

voltage. At the moment contact is made with the battery, the voltage across the capacitor is

A) greater than the battery's terminal voltage.

B) less than the battery's terminal voltage, but greater than zero.

C) equal to the battery's terminal voltage.

D) zero.

Definition
D) zero
Term

A resistor and a capacitor are connected in series to an ideal battery of constant terminal

voltage. At the moment contact is made with the battery, the voltage across the resistor is

A) greater than the battery's terminal voltage.

B) less than the battery's terminal voltage, but greater than zero.

C) equal to the battery's terminal voltage.

D) zero

Definition
C) equal to the battery's terminal voltage
Term

 A resistor and a capacitor are connected in series to an ideal battery of constant terminal

voltage. When this system reaches its steady-state, the voltage across the resistor is

A) greater than the battery's terminal voltage.

B) less than the battery's terminal voltage, but greater than zero.

C) equal to the battery's terminal voltage.

D) zero

Definition
D) zero
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