UNIT THREE

Question 1

what is the motor principle?

Answer 1

when magnets are placed in a perpendicular magnetic field, they will experience a force. magnitudes depend on amount of current in the wire.

Question 2

what is a galvanometer

Answer 2

device that measures the magnitude of small electric currents.

Question 3

what is an ammeter?

Answer 3

Used to measure current in amps

Question 4

what is Lenz Law?

Answer 4

if an induced magnet goes near a current it will oppose the magnetic field. if you pull it away it wants if you push it it doesn’t want

Question 5

What is domain theory?

Answer 5

who knows but i looked it up and it said large areas in magnets in which the magnetism of the individual atoms and molecules are all aligned in the same direction. so its how magnets be i suppose

Question 6

what is KCL series?

Answer 6

in a closed circuit, amount of current entering=amount leaving. I1=I2=I3…

Question 7

What is KCL parallel?

Answer 7

I parallel= I1+I2+I3…

Question 8

What is kvl series?

Answer 8

v series= v1+v2+v3

Question 9

what is kvl parallel?

Answer 9

v parallel= v1=v2=v3…

Question 10

what is resistance series?

Answer 10

R1=R2=R3

Question 11

WHAT is r parallel

Answer 11

1/RP= 1/R1 + 1/R2 + 1/R3…

Question 12

how do transformers work?

Answer 12

Honestly? i don’t know. they change the current or voltage to the amount needed. the current induced a magnetic field, magnetic field is changing, induces a current in the secondary coil.

Question 13

what do the coild have to do with anything

Answer 13

on a transformer, it affects voltage. if winding are low, voltage is also low.

Question 14

how does N, \v, and I change between coils in step up transformer?

Answer 14

primary             secondary
Np     <    NS
VP     <    Vs
IP      >     Is
THIS IS OPPOSITE IN STEP DOWN.

Question 15

how does a DC motor work?

Answer 15

the current flows in one direction, carbon brushes allow the current to flow through the loop. wen the loop is vertical (at max magnetic force) the carbon brushes are on insulators and brush keeps spinning due to inertia, before current changes so the magnet is reversed.

Question 16

what effects the strength of an electromagnet?

Answer 16

the current, (greater current = greater magnetic field)
the number of loops, (magnetic field = sum of all its loops. # loops = # electric)
type of core, (adding an iron core will strengthen the magnet as it will become an induced magnet)

Question 17

what is an electromagnet?

Answer 17

a device that exerts a magnetic force with electricity. its kinda telling

Question 18

what happens when current is bent into a coil?

Answer 18

it makes a magnetic field of a bar magnet

Question 19

what is true about straight conductors?

Answer 19

the magnetic fields are circular and do not touch, there are no poles, and field lines go opposite when the current is reversed.

Question 20

what is the third Right Hand Rule?

Answer 20

point fingers in direction of current (North to South) point your thumb in the direction of the current. pretend your palm is pushing it away.

Question 21

what is the second Right Hand Rule?

Answer 21

curl the fingers in the direction of the current, thumb points to the north pole.

Question 22

What is the first Right Hand Rule?

Answer 22

if the straight conductor is held in the right hand, the thumb points in the direction of the current and,the fingers curl in the direction of magnetic field lines

Question 23

how to calculate cost?

Answer 23

P=V^2/R or equivalent
make sure P is in kW
E= pt
Cost = consumption x price

Question 24

how to calculate mv to v?

Answer 24

divide mv by 1000

Question 25

1/rp?

Answer 25

1/rp = 1/r2 + 1/r3 (or whatever the line is in between)