series & parallel circuits- COMPLETE

[fickle solar]

Hi guys, we're learning abt series & parallel circuits in science but I'm confused about how the voltage divides itself between bulbs when it comes to parallel circuits... the answer for this is 4V, but I don't know how to get to that answer. Could someone pls run through how they'd figure this out step by step? thx :)

I'm also a bit confused about why some bulbs have crosses and others have Vs, but oh well lol that's less important

[cosmic vector]

In parallel circuit, the volvage is always the same for each bulb

Because the voltage formula for parallel circuit is Vt=V1=V2

Its different from series circuit where the formula for voltage is Vt=V1+V2

So the voltage is different for each bulb in series

Do you understand?

[fickle solar]

yeah that makes sense, thanks!

[fickle solar]

but how come w this parallel circuit the voltage is different for the bulbs?

[cosmic vector]

The parallel and series of a circuit can be identify as does the bulb is series or parallel from the battery in a circuit

From this pic you can see three different circuit

1. A circuit with only one bulb (6v) as it only has one
2. A circuit with 3 bulb (2v) for each if the resistance of all the bulb is same
3. A circuit with 2 bulb (3v) for each of the bulb if the resistance of the bulb is same

So the conclusion here for this pic it is not a parallel circuit but three diff series circuit

You can see it as parallel when you want to calculate the total voltage of the circuit

[fickle solar]

OHHHHH

that makes so much sense!!

I just have one more example I'm confused abt if thats ok! thank you so much for all your help btw

[cosmic vector]

Yeah you can ask

Welcome tho

[fickle solar]

I'm confused abt this one- I'm not sure what a1 and a2 stand for, and what specifically I'm supposed to calculate

I'm also not sure whether I'm supposed to use Olms law or not, so I'm not entirely sure where to start

could you walk me through it, if that's alright?

[cosmic vector]

If im not mistaken

A stands for current here

As its unit is A

It is easier if you separate voltage and current circuit so that you can see which one is in series and which one in parallel

And make two diff calculation

For voltage first, you can see that the main battery or the main voltage is parallel to a bulb AND two bulb

The two bulb is considered as a series circuit so you can add the value of two of them. But for this, as it does not give any value and you know that for series, Vt= V1 +V2, so you know the total voltage is 6v

It does not stated here right if the bulb is same or different, so just assume that the bulb is same and both voltage for the bulb is V2=3v and V3=3v

For V1, as it already parallel so the value is 6v

Then, for the current. You can two diff circuit that connected to the battery, one with a series circuit connection with 3A, A1 and A3
and another circuit that parallel to the battery which is A2

So, for series circuit, all current is equal, At=A1=A2

So, value of A3 = 3A

But for A1, as it have A2 that parallel with it, and formula of current in parallel circuit is At=A1+A2, so A1=1.5A and A2=1.5A

Im sorry if im wrong but the concept is like that

[fickle solar]

wait so is the voltage of the battery 3V?

[cosmic vector]

Its 6v

[fickle solar]

and how does it being parallel make the value 6V? Most of what you've said makes sense but I'm still a bit confused sry

[fickle solar]

ohhh wait ok I get that bit now I got mixed up👌

[cosmic vector]

Good good

You just need a ton like A TON of exercise to really master this topic tho

Because it will just get harder

[fickle solar]

Okay I get that bit, that makes sense! I didn't realise you had to break it down into series and parallel circuits

[fickle solar]

damn😭

[cosmic vector]

Its easier like that

[fickle solar]

it's mainly bc I missed a lot of classes for this so I didn't get it lol

I'm just gonna read through it again and make sure there's nothing I'm still confused abt rq!

[cosmic vector]

[fickle solar]

wait so which bulbs were you referring to here? im a bit confused bc aren't V2 and V3 parallel like V1 and so would be 6V?

[cosmic vector]

The battery is parallel to V1 and (V2 and V3)

But you can see that V2 and V3 is in series

Thats why V2 and V3 is 3v

[fickle solar]

but how are they in series? the circuit looks similar to V1's, if V3 broke that part of the circuit would be able to keep going right? maybe I'm just bad at telling them apart lol

[cosmic vector]

Heheh

You see

Like this

The battery and V1 are in series circuit

The battery and V2 and V3 are in series circuit

But if we want to combine both circuit, the circuit will become parallel

[fickle solar]

OHH

I guess I didn't think abt it like that bc the other crossed out bulbs and a2 were there- but that makes sense since we were separating voltage from current! is that what you meant?

thx for the (beautiful drawn) diagram lol it helped put it into perspective

[cosmic vector]

Hehe yes it iss

[cosmic vector]

Thank you🤣

[fickle solar]

so, just to clarify what ive learnt (hope this is isnt wrong)- with this example, even though its a parallel circuit, the two bulbs are 3V instead of 6V because in relation to the bulb, those two bulbs are a series circuit? if that makes sense? since parallel circuits are supposed to have the same voltage across the board but if there's a series circuit WITHIN that's when Vt=V1+V2

[cosmic vector]

YES

Its correct

[fickle solar]

thank you!!

tysm for all your help, I get it now :))

[cosmic vector]

Welcomee

[fickle solar]

is it ok if I friend request you in case I ever need more help with this in future? you seem rlly knowledgeable abt this stuff lol

[cosmic vector]

Yeah you cann

[cosmic vector]

I just graduate from my foundation

What grade are you in tho

[fickle solar]

Oh wow, congrats!!

[fickle solar]

Yr 9 lol

[fickle solar]

Physics-series & parallel circuits- COMPLETE