ELECTRICITY AND MAGNETISM

Question 1

e=elementart charge= charge of a single atomic particle= 1.6x10^-19

Answer 1

e= 1.6x10^-19 COLOUMBS
e-=    -1.6x10^-19 COLOUMBS
p+=   +1.6x10^-19 COLOUMBS

Question 2

1 coulomb = ?

Answer 2

6.24x10^18 atomic particle

Question 3

# of electron = # of protons = called?
# of electron ≠ # of protons = called?
more protons = called?
more electron = called?

Answer 3

neutral atom

charged atom/ ION

cation

anion

Question 4

when 1 coloumbs charge or 6.24x10^18 electrons passes through an imaginary cross section drifting in the same velocity, the flow of charge or current is said to be?

Answer 4

1 AMPERE

Question 5

1 ELECTRON PASSING THROUGH A CONDUCTOR HAS A CHARGE OF?

Answer 5

1.6X10^-19

Question 6

CURRENT FORMULA? IN TERMS OF CHARGE.

Answer 6

I= Q/A= COULOMBS / SECOND

Question 7

identify the current equivalent of the ff.
considered dangerous, can cause temporal paralysis ______

severe shock _______

fatal_______

Answer 7

> 10mA

> 50mA

> 100mA

Question 8

what are the two types of electricity

Answer 8

static and dynamic electricity

Question 9

difference of STATIC AND DYNAMIC ELECTROCITY

Answer 9

STATIC IS:
STATIONARY
TRANSFER OF ELECTRICITY IS ONE AT A TIME
TRAVELS IS AIR
OCCURS ON OPEN CIRCUIT
ALSO CALLED, ELECTRIC FLUX

DYNAMIC: 
MOVING
TRANSFER IS CONTINUOUS.   "CYCLE"
TRAVELS THROUGH CONDUCTORS
OCCURS IN CLOSED CIRCUIT
ALSO CALLED CURRENT

Question 10

FORULA OF COULOMBS LAW THAT IS SIMILAR TO THE GRAVITATIONAL LAW OF NEWTON

Answer 10

Fs=k(q1q2)/r^2 = electrostatic law = electrostatic force
q= charges
k=proportionality constant) = 9X10^9 Nm^2/C^2 (newton, meter, coulomb)
ε0= 8.854x10^-12 F/m (Farahd per meter)
ε0= vaccum permittivity

Question 11

states that: The net outward normal electric flux through any closed surface is proportional to the total electric charge enclosed within that closed surface divided by the permittivity.

Answer 11

gauss law, gauss’ flux theorem

Φelectric or = Ψ = Q/ε0 = electric flux

Question 12

electrostatic force VS electric field strength/intensity

Answer 12

electric field strength/intensity is the electrostatic force felt by a test charge from a source charge at a certain distance.

{Q= source charge | q= point charge}

Question 13

electric field strength/intensity

Answer 13

electric field strength = E = ξ = (Fs/q)
can also be derived to;
ξ= kQ/r^2
ξ= N/C or V/m (voltage over meter/ newton over coulomb)

Question 14

units of the following
k=?
Q or q = ?
ξ = ?
voltage = V = (by joules) =? 
I = current by time= ?

Answer 14

k=Nm^2/C^2
Q = coulomb
r = meter
ξ = N/C or V/m
V= J/C
I= Q/t

Question 15

prove that ξ is N/C or V/m

Answer 15

ξ = kQ/r^2 = [(Nm^2/C^2)(C)/ (m^2)] = Nm/Cm = J/Cm
[since J = Nm = ((Kgxm)/s^2) X m = Kgm^2/s^2 ]

and since, V= J/C then,

J/Cm = V/m

V/m = N/C

Question 16

SINCE ξ=V/m we can say that ξ=V/r (since r is in meter). transferring values will give result to V=ξr. PROVE THAT [ V = ∆Pe/q ]

Answer 16

V = ξr = Fs(r)/q (since we know that ξ =Fs/q) = W/q
(W= Fs x r since, force X distance = work)
= ∆Pe/q (becuase W is the change in potention energy)

Question 17

the magnitude of a magnetic, electric, or other flux passing through a unit area.

Answer 17

FLUX DENSITY

Question 18

FLUX DENSITY FORMULA BY FIELD STRENGTH

Answer 18

flux density = D = ξε0 = Ψ/A (flux/area)

Question 19

Voltage can be presented/equated as:

Answer 19

V= W/Q = J/C

Question 20

MAGNETIC FLUX LINE CAN ALSO BE CALLED

Answer 20

LINE OF FORCE

Question 21

MEASUREMENT OF LINE OF FORCE

Answer 21

MAXWELL (MX)

Question 22

signified GROUP OF LINES WHERE, and it’s equivalent in terms of maxwell

Answer 22

WEBBER (WB)

1WB = 1x10^8 MX

Question 23

is the measure of magnetization that a material obtains in response to an applied magnetic field.
or how easily can a magnetic field be be set up in a material

Answer 23

permeability ( μ)

Unit:
Webber over Ampere meter
W)/(A)(m

Question 24

magnetic counter part of resistance….

Answer 24

reluctance (FANCY R) (R)

WITH UNIT 1/HENRY

Question 25

formula for reluctance

Answer 25

R=reluctance

R= s l/A (s=reluctivity)
R =l / μA (μ= permeability)

Question 26

if resistance is the opposite of conductance and reluctivity is the opposite of permeability, what is the opposite of reluctance?

Answer 26

PERMEANCE
(FANCY P)
=(P)

-PROPERTY OF A MATERIAL TO ALLOW MAGENTIC FLUX TO BE ESTABLISED IN A MATERIAL

WHERE P=1/R
SO UNIT OF P = (HENRY)

Question 27

RATIO OF PERMEABILITY OF A MATERIAL WITH THAT OF FREE SPACE

Answer 27

RELATIVE PERMEABILITY (μr)

μr = μ/μ0

where μ0 = 4πx10^-7 H/m

Question 28

TYPE OF MAGNEETIC MATERIALS, GIVE EXAMPLE OF EACH AND GIVE THEIR μr

Answer 28

NON MAGNETIC=
AIR: μr =1

DIMAGNETIC=
COPPER: μr < 1

PARAMAGNETIC=
ALUMINUM μr > 1

FERROMAGNETIC=
IRON μr >= 1
(highed magnetic, 100X or 1000X more than free space)
* can retain magnetism even after magnetic field is removed.

Question 29

depine susceptibility

Answer 29

amount by which relative permeability differs from unity (1) or free space,

** HAS NO UNIT

Xm = μr - 1

Question 30

SI unit for flux is?

Answer 30

webber Φ

Question 31

flux density (B) is denoted as. and has unit _?

Answer 31

of flux lines / unit Area

Flux density with unit Tesla (T) = Wb/m^2
Flux density with unit Gauss (G) = Mx/cm^2

Question 32

ways to dislodge electron

Answer 32

thermionic emmision
photoelectric effect
triboelectric efffect - (friction)

Question 33

PRNCET MEANS??

Answer 33

PROTON RUTHERFORD
NEUTRON CHADWICK
ELECTRON THOMPSON

Question 34

electric flux Φe value when line of foce is along/perpendicular/angled to the area

Answer 34

Φe= EA   (PERPENDICULAR)
Φe= EA COSθ  (ANGLED)
Φe= 0  (ALONG MEANING THE LINE OF FORCE GRAZES THE AREA AND NOT CROSS IT ANYHOW)

Question 35

magnetic field around current carrtying wire
left hand screw rule is for the _____
right hand screw rule is for the ___

Answer 35

electron flow - left

conventional - right

(THUMB IS DIRCTION OF CURRENT, OTHER IS THE DIRRECTION OF THE MAGNETIC FIELD)

Question 36

direction of current iN solinoid OR COIL ?

Answer 36

USE right hand screw rule

where thumb is flux, and other is current flow.