Electrostatics And Magnetism

Question 1

Coulomb’s Law

Answer 1

Fe = kq1q2/(r^2)

Question 2

Electric field

Answer 2

E = Fe/q = kQ/(r^2)

Question 3

Electric Potential Energy

Answer 3

U = kQq/r

Question 4

Electric potential from electric potential energy charge

Answer 4

V = U/q

Question 5

Electric potential from source charge

Answer 5

V = kQ/r

Question 6

Voltage

Answer 6

Delta V = Vb-Va = Wab/q

Question 7

Electric potential near a dipole

Answer 7

V = kqd/(r^2) x cosØ

Question 8

Dipole moment

Answer 8

p = qd

Question 9

Electric field on the perpendicular bisector of a dipole

Answer 9

E = 1/4piE0 x p/(r^3)

Question 10

Torque on a dipole in an electric field

Answer 10

T = pEsinØ

Question 11

Magnetic field from a straight wire

Answer 11

B = u0I/2pir

Question 12

Magnetic field from a loop of wire

Answer 12

B = u0I/2r

Question 13

Magnetic force on a moving point charge

Answer 13

FB = qvBsinØ

Question 14

Magnetic force on a current-carrying wire

Answer 14

FB = ILBsinØ

Question 15

Coulomb unit

Answer 15

e = 1.60 x 10^-19 C

Question 16

Insulator

Answer 16

No easily distribute charge over surface or transfer
Usually nonmetals
Electrons of insulators much closer with their nuclei

Question 17

Conductor

Answer 17

Usually metal or ionic (electrolyte) solutions
Electrons farther form nuclei
Distribute charge across surface evenly

Question 18

Coulomb’s constant

Answer 18

k = 8.99 x 10^9 N(m^2)/(C^2)

Question 19

Permittivity of free space

Answer 19

E0 = 8.85 x 10^-12 (C^2)/N(m^2)

Question 20

Electric field vectors

Answer 20

Outwards for positive charges
Inwards for negative charges

Question 21

Direction of field and electrostatic force

Answer 21

Test charge + same direction as electric field vector of source charge, accelerate away, repulsive

Test charge - opposite direction to the field vector of source charge, accelerate towards, attractive

Question 22

Work

Answer 22

W (J) = FdcosØ

Question 23

Volts

Answer 23

J/C

Question 24

Electrostatic force is what kind of force

Answer 24

Conservative, pathway does not matter

Question 25

How do test charges move (change in electric potential) in relation with charge

Answer 25

Negative test charge, positive voltage change, negative Wab

Positive test charge, negative voltage change, negative Wab

In both U is decreasing

Question 26

Perpendicular bisector of the dipole

Answer 26

a line that cuts the electric dipole directly in half and does so at an 90 degree angle with respect to the line connecting the two charges of the electric dipole

Question 27

Electric field effect on electric dipole

Answer 27

An absence of electric field dipole axis can assume any random orientation

In the presence of a uniform external electric field, each of the equal and opposite charges of the dipole, will experience a force exerted on it by the field

Forces acting on the charges will also be equal in magnitude and opposite in direction, resulting in translational equilibrium

Question 28

Magnetic field

Answer 28

Created by moving charges
Can be created by individual charges moving like electron through space
Mass movement of charge in the form of a current through conductive material

Question 29

Unit for magnetic field

Answer 29

1 Tesla (T)= 1 N•s/m•C
1T = 10^4 gauss

Question 30

Diamagnetic

Answer 30

Made up on atoms w no unpaired electrons
No magnetic field
Weakly antimagnetic
Wood, plastic, water, skin, glass

Question 31

Paramagnetic materials

Answer 31

Weakly magnetized in the presence of external magnetic field
Removal of external field, thermal energy of individual atoms cause magnetic dipoles to reorient
Aluminum, copper, gold

Question 32

Ferromagnetic

Answer 32

Unpaired electrons
Permanent atomic magnetic dipoles
Normally oriented randomly so no magnetic dipole
Strongly magnetized when under certain thermal or magnetic field conditions
Impossible to have monopole
Iron, nickel, cobalt

Question 33

u0

Answer 33

Permeability of free space
4pi x 10^-7 (T•m/A)

Question 34

Lorentz force

Answer 34

Sum of electrostatic and magnetic charges