Physics Final

Question 1

The preferred positive direction for angular displacement is the clockwise direction.

Answer 1

False

Question 2

When a rigid body rotates about a fixed axis all the points in the body have the same angular displacement.

Answer 2

True

Question 3

When a rigid body rotates about a fixed axis all the points in the body have the same angular speed.

Answer 3

True

Question 4

When a rigid body rotates about a fixed axis all the points in the body have the same linear displacement.

Answer 4

False

Question 5

When a rigid body rotates about a fixed axis all the points in the body have the same tangential speed.

Answer 5

False

Question 6

When a rigid body rotates about a fixed axis all the points in the body have the same angular acceleration.

Answer 6

True

Question 7

When a rigid body rotates about a fixed axis all the points in the body have the same tangential acceleration.

Answer 7

False

Question 8

What is the quantity used to measure an object’s resistance to changes in rotational motion?

Answer 8

moment of inertia

Question 9

A solid sphere, solid cylinder, and a hollow pipe all have equal masses and radi. If the three are released simultaneously at the top of an inclined plane, which will reach the bottom first?

Answer 9

sphere

Question 10

Two children ride on a merry-go-round, George is at a greater distance from the axis of rotation than Jacques. It is a true statement that

Answer 10

Jacques and George have the same angular velocity.

Question 11

Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger linear displacement?

Answer 11

Child A

Question 12

Two children are riding on a merry-go-round. Child A is at a greater distance from the axis of rotation than child B. Which child has the larger angular displacement?

Answer 12

They have the same non-zero angular displacement.

Question 13

Two equal forces are applied to a door. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force exerts the greater torque?

Answer 13

the second at the doorknob

Question 14

A person sits on a freely spinning lab stool (no friction). When this person extends her arms,

Answer 14

her moment of inertia increases and her angular velocity decreases.

Question 14

An ice skater doing a spin pulls in her arms, decreasing her moment of inertia by a factor of two. How does her angular speed changes?

Answer 14

it increases by a factor of two.

Question 15

A figure skater is spinning slowly with arms outstretched. She brings her arms in close to her body and her moment of inertia decreases by 1/2. Her angular speed increases by a factor of

Answer 15

2

Question 16

A figure skater is spinning slowly with arms outstretched. She brings her arms in close to her body and her angular speed increases dramatically. The speed increase is a demonstration of

Answer 16

conservation of angular momentum: her moment of inertia is decreased, and so her angular speed must increase to conserve angular momentum.

Question 17

A heavy boy and a lightweight girl are balanced on a massless seesaw. If they both move forward so that they are one-half their original distance from the pivot point, what will happen to the seesaw?

Answer 17

Nothing, the seesaw will still be balanced.

Question 18

An ice skater doing a spin pulls in her arms, decreasing her moment of inertia by a factor of two, and doubling her angular speed. Her final rotational kinetic energy

Answer 18

is doubled.

Question 19

A merry-go-round spins freely when Janice moves quickly to the center along a radius of the merry-go-round. It is true to say that

Answer 19

the moment of inertia of the system decreases and the angular speed increases.

Question 20

An electrically neutral atom does not have a net charge.

Answer 20

True

Question 21

A neutron carries a negative charge.

Answer 21

False

Question 22

A neutron is approximately twice as heavy as the electron.

Answer 22

False

Question 23

The coulomb, which is the unit of charge, is the charge on one electron.

Answer 23

False

Question 24

Electric charge is quantized.

Answer 24

True

Question 25

A good conductor of electricity is a bad conductor of heat.

Answer 25

False

Question 25

The Coulomb force between two charges can be attractive or repulsive.

Answer 25

True

Question 26

A positive charge placed in an electric field experiences a force in the direction of the field.

Answer 26

True

Question 26

When the distance between the two charges is doubled, the force between them is

Answer 26

reduced by a factor of 4.

Question 27

Two charges, Q1 and Q2, are separated by a certain distance. The ratio of charge @1 to charge 2 is 1:2. The ratio of force on @1 to the force on @2 is

Answer 27

1:1.

Question 28

The main difference between conductors and insulators is in terms of so neutrons.

Answer 28

valence or conduction electrons.

Question 28

Two objects, A and B, are rubbed together. As a result, object A acquires an excess negative charge while object B becomes positively charged. In comparison to their masses before the charging process, you can say that

Answer 28

the mass of A increased and that of B decreased.

Question 29

Electrical and gravitational forces follow similar equations with one main difference:

Answer 29

Gravitational forces are always attractive but electrical forces can be attractive or repulsive.

Question 30

When atom A loses an electron to atom B,

Answer 30

atom A becomes a positive ion and atom B becomes a negative ion.

Question 31

The charge on the proton is the same as

Answer 31

The charge of an electron, but opposite sign

Question 32

The number of protons in the nucleus of an electrically neutral atom is equal to

Answer 32

the number of electrons surrounding the nucleus.

Question 33

Electric potential is a scalar quantity.

Answer 33

True

Question 34

When a proton moves in a direction of the electric field, its potential increases but its potential energy decreases.

Answer 34

True

Question 34

When an electron moves in a direction opposite to the electric field, its potential increases but the potential energy decreases.

Answer 34

True

Question 35

Unlike electric potential, the electric potential energy is a vector quantity.

Answer 35

False

Question 35

Conventional current is the flow of positive charge from higher to lower potential.

Answer 35

True

Question 36

Electron flow is in the direction of conventional current.

Answer 36

False

Question 37

A series circuit is a current divider and a parallel circuit is a voltage divider circuit.

Answer 37

False

Question 38

Four unequal resistors connected in series have same current but different voltages.

Answer 38

True

Question 39

Four equal resistors connected across a DC voltage source in either series or parallel will have equal voltage drops across each resistor.

Answer 39

True

Question 40

Four equal resistors connected in series have same current and same voltage across each resistor

Answer 40

True

Question 41

Which one of the following is the correct statement regarding the resistance?

Answer 41

The resistance of a wire is directly proportional to the length of the wire.

Question 42

The length of a certain wire is kept same while its radius is doubled. What is the change in the resistance of this wire?

Answer 42

It is reduced by a factor of 4.

Question 43

Four unequal resistors are connected in a parallel circuit. Which one of the following statements is correct about this circuit?

Answer 43

The total resistance is less than the smallest resistor.

Question 44

Four unequal resistors are connected in a series circuit. Which one of the following statements is correct about this circuit?

Answer 44

The total resistance is more than the largest resistor.

Question 44

Which of the following statements is correct?

Answer 44

The north pole of a magnet points towards the Earth's geographic north pole.

Question 45

The field near a long straight wire carrying a current is inversely proportional to the current flowing through the wire.

Answer 45

False

Question 45

The magnetic field near a current carrying wire is directly proportional to the distance from the wire.

Answer 45

False

Question 46

A current carrying wire placed in a magnetic field perpendicular to the wire experiences a maximum force.

Answer 46

True

Question 47

At a given location the direction of the magnetic field is the direction that the north pole of a compass points when placed at that location.

Answer 47

True

Question 48

Magnetic field lines can never cross one another.

Answer 48

True

Question 49

Magnetic field lines come out of the south pole of a magnet and enter at the north pole.

Answer 49

False

Question 49

An electron moving in the positive y direction, at right angles to a magnetic field, experiences a magnetic force in the negative x direction. What is the direction of the magnetic field?

Answer 49

It is in the positive z direction.

Question 50

According to the law of reflection of light, the angle of incidence is

Answer 50

equal to the angle of reflection.

Question 51

Which one of the following is the correct number for the magnification of a plane mirror?

Answer 51

1.0

Question 52

The angle of reflection is the angle between

Answer 52

the reflected ray and the normal drawn at the point where this ray meets the mirror

Question 53

The angle of incidence is the angle between

Answer 53

the incident ray and the normal drawn at the point where this ray meets the mirror.

Question 53

The image formed in a plane mirror is

Answer 53

at the same distance behind the mirror as the object is in front of the mirror

Question 54

Which of the following sets of characteristics describes the image formed by a plane mirror?

Answer 54

virtual and upright