Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics > Chapter 8 - Electrostatics and Electromagnetism > Flashcards

Chapter 8 - Electrostatics and Electromagnetism Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What are electric field lines? What is their directionality and strength?

A

They are lines of force representing an electric field. They always originate on a positive charge and end on a negative charge. They represent the way a positive charge would migrate. Field lines close together mean the electric field is strong, whereas field lines farther apart mean the electric field is weak.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a test charge (q’)?

A

an arbitrary positive charge with an electric field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Equation: Faraday’s law of electromotive force

A

emf = -ΔφB/Δt

φB = magnetic flux

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Equation: electric dipole moment

A

P = qL

q = product of the charge

L = distance separating charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is meant by dielectric behavior of a medium?

A

A strongly polar medium (high K) responds to an external electric field by reorienting its polar molecules so that the net electric field within the medium becomes weaker than the external field. (δ+ charges of the medium align with the negative plate and δ- charges align with the positive plate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mass of an electron

A

9.11 x 10-31 kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Diagram of electric field

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the net force on an electric dipole in a uniform electric field?

A

zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the units of electrical potential energy?

A

J

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Equation: change in electrical potential energy

A

ΔPEq = kq1q2 (1/rf - 1/ri)

ri = initial separation of charges

rf = final separation of charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Equation: magnetic field force

A

Fmagnetic = qvB⊥ = qvBsinθ

v = velocity

B = magnetic field

θ = angle between v and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Equation: electrical potential difference of a moving charged particle (2 versions)

A

VAB = ΔPEAB/q

ΔPEq = qV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When a charged particle moves with velocity through a magnetic field, at what position is the magnetic force strongest? Weakest?

A

velocity perpendicular to magnetic field: greatest force

volecity parallel to magnetic field: smallest force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Equation: electric field

A

E = F/q = mg/q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a conductor?

A

a material that allows for the movement of a charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are equipotential lines? What is their positional relation to field lines?

A

They are lines that connect all points within an electric field sharing the same potential. They are perpendicular to field lines.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the units of electrical potential energy difference?

A

J/C = volt (V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the unit of an electric field?

A

N/C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is an absolute potential?

A

Voltage measurements at points in space relative to the ground point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

About how much greater is the mass of a proton than the mass of an electron?

A

~2000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the units of magnetic fields?

A

N•s/C•m or N/A•m = T (tesla)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Diagram of magnetic field

A
23
Q

What is Lenz’s law of conducting loops?

A

As a conducting loop enters a magnetic field, the loop experiences an induced current that creates a magnetic field in the opposite direction. When it is immersed in the field, it experiences no current. When it exits, it again creates a magnetic field, this time opposite the one it made.

24
Q

Equation: Coulomb’s law of electrical force

A

F = k (|q1q2|)/r2

k = proportionality constant = 8.99 x 109 N•m2/C2

25
Q

Equation: torque on a conducting loop within a magnetic field

A

τ = NIAB sinφ

N = # of turns

I = current

A = area of loop

B = external magnetic field

φ = angle between external field and loop’s field

26
Q

Charge of an electron

A

-1.6 x 10-19 C

27
Q

What is a solenoid?

A

a helical winding of a conducting wire wound on a cylindrical tube where the length is at least four times its radius

Upon passing current through a solenoid, it can generate a linear magnetic field.

28
Q

Equation: torque of electric dipole in a uniform electric field (2 versions)

A

τ = (pE)(sinθ) = (qE)(Lsinθ)

p = dipole

29
Q

Equation: dielectric constant

A

K = Fvacuum/Fmedium

30
Q

Mass of a neutron

A

1.673 x 10-27 kg

31
Q

When a test charge moves in the direction of a field line, it moves from higher/lower potential to higher/lower potential?

A

It moves from higher to lower potential.

32
Q

How can electrical potential energy between two charges be changed?

A

If you must do work to move two charges, you have increased their PE (bring two like charges together, pulling opposite charges apart).

If the charges move naturally, they are decreasing their PE (bring two opposite charges together, pulling like charges apart).

33
Q

When a solenoid generates a mangetic field, what is that field dependent upon?

A
  • current (I) passing through the solenoid
  • solenoid dimensions
34
Q

What is charge conservation?

A

The total electric charge on two objects in a system does not change. Even though the charge can be transferred from one object to the next, it cannot be created or destroyed.

35
Q

Charge of a proton

A

1.6 x 10-19 C

36
Q

When an electric dipole (p) is introduced into a uniform electric field (E), at which position is its potential energy the greatest? the least?

A

dipole perpendicular to electric field: zero PE

dipole parallel to electric field: most stable, negative PE

dipole antiparallel to electric field: least stable, positive PE

37
Q

What are the units of charge?

A

coulomb (C)

38
Q

What is an insulator?

A

a material that impedes the movement of charge

39
Q

Equation: potential energy of electric dipole in a uniform electric field

A

PE = - (pEcosθ)

40
Q

Right-hand rule of magnetic force

A

thumb = velocity of positively charged particle

fingers = direction of magnetic field

palm = magnetic force

*If particle is negative, the force will be opposite

41
Q

Right-hand rule for current in magnetic field

A

Thumb = direction of magnetic field B

Curled fingers = CW/CCW direction of current

42
Q

Mass of a proton

A

1.673 x 10-27 kg

43
Q

How do equipotential lines correlate with work done on a test charge?

A

If the test charge is placed at any point along an equipotential line, the electric field does no work on that test charge.

44
Q

Equation: exit speed of a charged particle in a velocity selector

A

v = E/B

45
Q

Equation: mass spectrometer radius/mass correlation

A

r = mv/qB

46
Q

What is an electrical ground point?

A

An electrical point of reference with a voltage of 0.

47
Q

Diagram of symbols for magnetic field into or out of page

A
48
Q

When an electric dipole (p) is introduced into a uniform electric field (E), at which position is its torque the greatest? the least?

A

dipole perpendicular to field = greatest torque

dipole parallel/antiparallel to field = least torque

49
Q

Equation: electric force in a field

A

Felectric = qE = mg

50
Q

Equation: electric work (2 versions)

A

W = qEΔd = qΔV

51
Q

Equation: velocity of charged particle in electric field

A

Vf = √(2qΔV/m)

52
Q

Equation: force on conducting loop in a magnetic field

A

F = Il x B

I = current

l = length of loop

B = magnetic field

53
Q

Do electric fields and magnetic fields have the ability to accelerate a charged particle from rest?

A

Electric fields can, magnetic fields cannot.

54
Q

Do electric fields and magnetic fields do work on a charged particle?

A

Electric fields can, magnetic fields cannot.

Physics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions