What is the current in this circuits?

[PhysicsNewbie321]

Homework Statement

Homework Equations

Ohm's Law : V = IR, Eel = VIt , Vt=ItRt , Q=It

The Attempt at a Solution

I tried to do the first question letter a

I=? I= V/R
R=3 ohms I= 6/3
V=6V I=2A[/B]

i don't know how to continue the others :/

 

[Merlin3189]

So far, so good, so long as you know what it is that you have worked out.

Your final line says, V=6V I=2A so now you know V,I and R for the 6Ω resistor

So now, what do you know about the 3Ω resistor?

 

[PhysicsNewbie321]

So far, so good, so long as you know what it is that you have worked out.

Your final line says, V=6V I=2A so now you know V,I and R for the 6Ω resistor

So now, what do you know about the 3Ω resistor?

I don't know if I can work out b) without any given volts in the 2nd 1ohm resistor

 

[gneill]

I don't know if I can work out b) without any given volts in the 2nd 1ohm resistor

What type of circuit is depicted? Is it series-connected or parallel-connected?

 

[Merlin3189]

I don't know if I can work out b) without any given volts in the 2nd 1ohm resistor

But you haven't said what you DO know about it!
I'll give you a start. You know R is 1Ω. Now, can you tell me what I or V is? (without doing any calculation yet.)

If you say you know neither I nor V, you could try drawing on the circuit, or think about gneill's question,. .Because you DO know one of them! And you only need 2 out of 3 to work out the other.

 

[PhysicsNewbie321]

What type of circuit is depicted? Is it series-connected or parallel-connected?

its connected in series meaning voltage is divided among components.

But you haven't said what you DO know about it!
I'll give you a start. You know R is 1Ω. Now, can you tell me what I or V is? (without doing any calculation yet.)

If you say you know neither I nor V, you could try drawing on the circuit, or think about gneill's question,. .Because you DO know one of them! And you only need 2 out of 3 to work out the other.

V - volts , I - current.

I don't know the volts of the battery

 

[cnh1995]

I don't know the volts of the battery

You need not know that.

its connected in series meaning voltage is divided among components.

What else does that mean? What about the current through the series components?

 

[PhysicsNewbie321]

You need not know that.

What else does that mean? What about the current through the series components?

series same current

 

[gneill]

series same current

So then, what is the current through the 1 Ω resistor?

 

[PhysicsNewbie321]

So then, what is the current through the 1 Ω resistor?

2A?

 

[gneill]

2A?

Yes. It's a series circuit so there is only one current.

 

[PhysicsNewbie321]

Yes. It's a series circuit so there is only one current.

thanks

 

[cnh1995]

2A?

Yes. So what is the voltage across the 1 ohm resistor?

 

[PhysicsNewbie321]

Yes. So what is the voltage across the 1 ohm resistor?

for b) 2A

c) v=Ir
2x1=2volts

 

[cnh1995]

for b) 2A

c) v=Ir
2x1=2volts

Yes. Now you have sufficient information to calculate the p.d. across the battery.

 

[PhysicsNewbie321]

Yes. Now you have sufficient information to calculate the p.d. across the battery.

for d) is it 6V + 2V = 8V?

e) each cell has 2v?

 

[cnh1995]

for d) is it 6V + 2V = 8V?

e) each cell has 2v?

Yes.

 

[PhysicsNewbie321]

Yes.

Thanks that's a question done.

For the next problem,

a) 1.5x4 = 6V
b)
V?
R=6ohm
I= 1? (v/ohm,6/6)

6x1=6V?

c) 1A?

thanks a lot man

 

[cnh1995]

Thanks that's a question done.

For the next problem,

a) 1.5x4 = 6V
b)
V?
R=6ohm
I= 1? (v/ohm,6/6)

6x1=6V?

c) 1A?

thanks a lot man

Yes.

 

[PhysicsNewbie321]

Yes.

d)

v=?
r=3ohm
i=2a(6/3)

v=ir 2x3 = 6V?

e)2A?

but how come can both be 6V when its a 6V battery?

 

[cnh1995]

but how come can both be 6V when its a 6V battery?

What can you say about the voltage across two parallel components?

 

[PhysicsNewbie321]

What can you say about the voltage across two parallel components?

a i see constant pd

thanks

 

[PhysicsNewbie321]

What can you say about the voltage across two parallel components?

e) 2A

f) 2a+1a = 3A

g) 1/6 + 1/3 = 1/2 = 2A?

@cnh1995

 

[cnh1995]

e) 2A

f) 2a+1a = 3A

Yes.

) 1/6 + 1/3 = 1/2 = 2A ** ohm**?

 

[PhysicsNewbie321]

Yes.

my mistake.. its ohms.

thanks for all your help !