Units and Equations - Section 2

Question 1

Magnetic Fiel Equation

Answer 1

B = F/|q0|(v X sin (theta))

Question 2

Magnetic Field Units

Answer 2

Newton X Second/Coulomb X meter = Tesla

Question 3

Centripetal Force

Answer 3

F(c) = mv^2/r

r= mv/|q|B

Question 4

Magnectic Force on a current carrying wire of a certain length

Answer 4

F = ILB X sin (theta)

Question 5

Net torque on a current carrying coil

Answer 5

t = NIA X (B X sin (theta))

N= # of turns in coil
A= length X width

Question 6

Magnetic moment

Answer 6

NIA

Question 7

Magnectic moment units

Answer 7

Ampere X meter^2 (A X m^2)

Question 8

Torque units

Answer 8

Newton X meter

Question 9

Magnetic Field of a wire

Answer 9

B = (u0 X I)/(2)(pi)(r)

Question 10

Magnetic Field of a circular loop

Answer 10

B = N X (u0 X I0/2R

Question 11

Magnetic Field of a solenoid

Answer 11

B = u0 X n X I

Question 12

Permeability of free space

Answer 12

u0 = 4pi X 10^-7 T X m/A

Question 13

Ampere’s Law

Answer 13

Sum of (B||delta L) = u0 X I

Question 14

Motional EMF equation

Answer 14

& = vBL
v=velocity
L=length

Question 15

Motional EMF units

Answer 15

Volts

Question 16

Magnetic Flux equation

Answer 16

BA X cos (theta)

Question 17

Magnetic Flux units

Answer 17

Tesla X meter squared = Weber (Wb)

Question 18

Farraday’s Law of Electromagnetic Induction

Answer 18

& = - N X (change in magnetic flux/ change in time)

N = # of loops in coil

Question 19

Induced emf in a rotating planar coil in a generator

Answer 19

& = NABw X sin (theta)

theta = wt 
w= 2(pi)f

NABw = &max

Question 20

Current drawn by a motor

Answer 20

I = V - &/ R

R= resistance

Question 21

Emf due to mutual inductance

Answer 21

&(s) = -M X (change in current in primary coil / change in time)

M = # of loops in secondary X magnetic flux of secondary / current in primary

Question 22

Mutual inductance units

Answer 22

V X s/A = Henry (H)

Question 23

Emf due to self inductance

Answer 23

& = -L X (change in current / change in time)

L = # of loops X magnetic flux / change in time

Question 24

Self inductance units

Answer 24

V X s/A = Henry (H)

Question 25

Energy stored in an inductor

Answer 25

E = .5 X LI^2

L = self inductance

Question 26

Energy Density

Answer 26

Energy/Volume = 1/2(u0) X B^2

Question 27

Transformer equation

Answer 27

V(s) / V(p) = N(s) / N(p)

I(s) / I(p) = N(p) / N(s)