SET flashcards, inductance + ohems law wheel

combination circuit refresh steps

1) Reduce series branches

2) Reduce parallel branches

3) combine R in parallel

4) combine the new series resistors

Circuits w 2 batteries in parallel

Ignore one battery at a time and solve for component per battery, Add values from component at the end to get the true value for it.

what is voltage?

the difference of voltage potential between two points

1 amp =

1 coloumb/ 1 second

1 volt =

1 joule / 1 colomb

power =

energy / time

Layers of NEC biggest to smallest

chapters, articles, parts, sections, subsections.

how is an ameter connected?

in series, low R.

how is a voltmeter connected?

in parallel, high R

how is an ohemeter connected?

its not! its used alone outside the circuit on a single part

what does a multimeter/VOM do?

measure V, I, or R.

what is inductance?

when a mag field cuts thru a conductor, it creates another V or I in it.

which way does induced V or I travel?

it travels the opposite way, opposite polarity.

inductance definition…what do inductors do?

tendancy to oppose changes in I due to a mag field…Inductors OPPOSE change in I.

Relationship between I and induced V

Amt of induced V is proportional to the change in I

What is bonding?

physically connecting metals to form a constant low R path by bonding (physically connecting them) to the Neutral conductor.

why is bonding done>

to make an effective ground fault current path of low R to clear a ground fault.

How does bonding work?

connects H to N (groundED conductor)..which creates a short to create a ground fault…that open the circuit breaker…to save u from a shock.

Elements of a bonded system?

Low R bonding path, internal, I surges to go thru circuit breaker, equipment grounding conductor (Ground wire….EGC).

What is grounding?

using grounding method to connect Neutral to Ground wire for ground faults.

how do u do grounding?

connect N wire to Ground wire.

why do we ground stuff?

to lower induced V on metal and eletrical systems.

elements of grounding something

electric system, external, V surge goes thru the earth ground, grounding electrode conductor (GEC) which is the wire to the ground rod, grounding electrode (GE) which is the ground rod.

Grounding and bonding is talked about in NEC 250

mark in the book

Why do we want to aviod having loops and bends in our grounding system?

bc they induce I (impedence) that raises resistance - destroying the LOW R path we want!

the word “system” means…

transformer. TFs bond N to G outside.

what happens if V is too high on coils?

they jump rings instead of flowing down them, causing overheating.

fact

the grounding electrode conductor (GEC, copper wire to ground rod) is bonded to the ground wire form the panel that goes to the ground electrode rod in the earth.

V in parallel vs series

V in parallel is same everywehere. V in series is added for V source.

I in parallel vs series

I in parallel is added, I in series is same everywhere.

parralel and series circuits other names

parallel: current dividers. Series: voltage dividers.