Physics 112 Exam 2

Front 1

Magnets

Like poles _____

Unlike poles _____

Are magnetic monopoles found in nature?

Back 1

Like poles repel

Unlike poles attract

No

Front 2

Magnetic fields are always ____ ____

They emerge from the ____ pole and enter the ___ pole

Back 2

-Magnetic fields are always closed loops.

-They emerge from the north pole and enter the south pole.

Front 3

Describe the right hand rules

Back 3

Front 4

A ____ charge has an E field and no B field associated with it.

A ____ charge has an E field and B field associated with it.

Back 4

A static charge has an E field and no B field associated with it.

A moving charge has an E field and B field associated with it.

Front 5

-Two parallel currents exert a ___ on each other.

-Parallel currents ___

-Antiparallel currents ___

-Notice that the force on one wire is due only to the field produced by the other wire. Wires don't produce a force on themselves.

Back 5

-Two parallel currents exert a force on each other.

-Parallel currents attract

-Antiparallel currents repel

Front 6

How do you calculate the force between two parallel current-carrying wires?

Back 6

F= uo I1 I2 L2 / 2pi d

Front 7

-Maximum torque occurs when the coil's face is ____ to the magnetic field. And when the magnetic moment/rotational axis is ___ to the B field

Back 7

parallel, perpendicular

Front 8

1. F= ILBsin(theta)-> theta is between?

2. F= qvBsin(theta) -> theta is between?

3. torque= NIABsin(theta) -> theta is between?

Back 8

1. Current (I) and magnetic field (B)

2. Velocity (v) and magnetic field (B)

3. Magnetic moment (M) and Magnetic field (B)

Front 9

-Region A: induced current will be ___

-Region B: induced current will be ___

Back 9

-CCW (region is gaining flux into the page)

-CW (region is losing flux into the page)

Front 10

____ forces associated with eddy currents can dramatically slow a conductor moving into or out of a magnetic field

Back 10

Drag

Front 11

Induced emf _______ the original flux change

Back 11

Induced emf opposes the original flux change

Front 12

Changing ___ ___ induces an electric field

(and vice-versa)

(extra term in maxwell equations)

Back 12

Changing magnetic field induces an electric field

(extra term in maxwell equations)

Front 13

Electric generator converts ___ energy to ___ energy.

Back 13

Electric generator converts mechanical energy to electrical energy.

Front 14

Changing magnetic flux in the coils induce an ___, which drives an alternating current through an external circuit.

Back 14

Changing magnetic flux in the coils induce an emf, which drives an alternating current through an external circuit.

Front 15

-Initially:

-With time:

-Eventually:

Back 15

-Initially: A large emf develops across L to oppose the increasing current. (most emf across L)

-With time: I increases less rapidly

-Eventually: All the voltage drop is across R

Front 16

Right hand rule for EM waves

Back 16

Front 17

The magnetic and electric fields are ____ to each other

Back 17

The magnetic and electric fields are perpendicular to each other

Front 18

Looking into a plane flat mirror, the image behind it is ___ and the ____ ____

Back 18

Looking into a plane flat mirror, the image behind it is virtual and the same size (as the object)

Front 19

Concave Mirror

Outside C

Back 19

smaller, inverted, real

Front 20

Concave Mirror

Between C and F

Back 20

larger, inverted, real

Front 21

Concave Mirror

Inside F

Back 21

Larger, upright, virtual

Front 22

Convex Mirror

Back 22

Smaller, upright, virtual

Front 23

Sign Conventions for Spherical Mirror

Back 23

Front 24

Converging Lens

Beyond F'

Back 24

inverted, real

Front 25

Converging Lens

Inside F'

Back 25

Upright, virtual, larger

Front 26

Diverging lens

Back 26

Upright, virtual, smaller

Front 27

Sign conventions for lenses

Back 27

Front 28

-Converging lens focuses incoming parallel rays to a ___

-Diverging lens spreads incoming rays so that they appear to come from a point ___ the lens

Back 28

-Converging lens focuses incoming parallel rays to a point.

-Diverging lens spreads incoming rays so that they appear to come from a point before the lens.

Front 29

Magnetic field in a solenoid

Back 29

Front 30

A negative charge (-Q) is placed at rest near a magnet. Will the charge begin to move? Will it feel a force?

Back 30

No

A charge at rest has velocity equal to zero; magnetic fields exert a force only on moving electric charges.

Front 31

Back 31

an inductor always resists change in magnetic flux. The induced emf will oppose change.