Ive done that by using I X R

I1 200A X 0.012 Ohms I get 2.4
I2 160A X 0.015 Ohms I get 2.4
I3 300A X 0.008 Ohms I get 2.4

I have tried drawing a schematic, but its not helped with the second question, so I will leave that for now, and ask the tutor for advice.

But you didn’t try what WBahn had suggested. What is the equivalent resistance of 0.012Ω, 0.015Ω and 0.008Ω in parallel?

With that equivalent resistance, what is the current drawn from a 2.4VDC source?

 

But you didn’t try what WBahn had suggested. What is the equivalent resistance of 0.012Ω, 0.015Ω and 0.008Ω in parallel?

With that equivalent resistance, what is the current drawn from a 2.4VDC source?

Do you mean the Resistance Total? which is 275.

 

275 what? Volts, Amps, Ohms or Ferbles? Might as well be the last.

Several times you have been admonished to use a reasonable test. If all resistances are less than 0.02Ω, does an answer of 275 Ferbles make sense?

 

275 what? Volts, Amps, Ohms or Ferbles? Might as well be the last.

Several times you have been admonished to use a reasonable test. If all resistances are less than 0.02Ω, does an answer of 275 Ferbles make sense?

Sorry, 275 ohms.

 

Ok, did you read the second half of my reply?

Several times you have been admonished to use a reasonable test. If all resistances are less than 0.02Ω, does an answer of 275Ω make sense?

 

Ok, did you read the second half of my reply?

Yes, the value of 275 ohms is too high for the resistance, so something is wrong somewhere.

Redone the calculation, and got a value of 0.0036.

 

Hello,

Have a look at this page of the eBook:
https://www.allaboutcircuits.com/textbook/direct-current/chpt-5/simple-parallel-circuits/

Bertus

 

And now to check your answer. What is the equivalent resistance times the total current draw?

 

And now to check your answer. What is the equivalent resistance times the total current draw?

It’s 2.376 volts.

 

And what does that mean? Don’t just blindly post numbers. You have to be able to tell (and describe) what they mean.

 

And what does that mean? Don’t just blindly post numbers. You have to be able to tell (and describe) what they mean.

It means that the the voltage across the circuit is the same as the supply voltage.

 

Ive done that by using I X R

I1 200A X 0.012 Ohms I get 2.4
I2 160A X 0.015 Ohms I get 2.4
I3 300A X 0.008 Ohms I get 2.4

I have tried drawing a schematic, but its not helped with the second question, so I will leave that for now, and ask the tutor for advice.

But what do you get for the effective resistance of the three resistors?

We know that multiplying the current by the resistance will yield 2.4 V because that's how we got the current values in the first place. While it does provide some utility as a check against fumble-fingered calculations, finding the equivalent resistance and using that and the 2.4 V to show that you get the same 660 A is a much better one.

Go ahead and draw the schematic and answer the second question for THAT schematic. Basically, it's just asking for the current in each wire attached to each node. It's not hard at all to solve, it's just that there are lot's of ways to connect the components and still have them all be in parallel.

 

Do you mean the Resistance Total? which is 275.

I don't know how many times I have to say it or how many times you have to keep screwing up because you won't listen.

TRACK YOUR UNITS!

If you had bothered to do that, you would see that your 275 have units of 1/Ω and not Ω. That would have IMMEDIATELY told you that your answer was wrong.

But, no. You insist on ignoring units, making mistakes, and foregoing the opportunity to catch them and correct them.

If you were working for me and displayed this level of refusal to use the single most powerful error detection tool available to the engineer, I would have already fired you.

 

It’s 2.376 volts.

That's what you get for reporting the equivalent resistance to just two sig figs and then a subsequent calculation using it to four sig figs.

 

It means that the the voltage across the circuit is the same as the supply voltage.

Is it?

You say that the equivalent resistance is 0.0036 Ω and that the total current is 660 A.

What is the current that flows from a 2.4 V supply into a 0.0036 Ω resistance?

Where's that additionl 6.66 A going?

 

I don't know how many times I have to say it or how many times you have to keep screwing up because you won't listen.

TRACK YOUR UNITS!

If you had bothered to do that, you would see that your 275 have units of 1/Ω and not Ω. That would have IMMEDIATELY told you that your answer was wrong.

But, no. You insist on ignoring units, making mistakes, and foregoing the opportunity to catch them and correct them.

If you were working for me and displayed this level of refusal to use the single most powerful error detection tool available to the engineer, I would have already fired you.

I know it’s silly errors. I will double check my workings out from now on.

 

That's what you get for reporting the equivalent resistance to just two sig figs and then a subsequent calculation using it to four sig figs.

I’m not sure what you mean?

 

I know it’s silly errors. I will double check my workings out from now on.

Don't just double check your workings. TRACK YOUR UNITS!

If you will just do that one thing, religiously, you will see your grades go through the roof.

 

I’m not sure what you mean?

Do some Google searching on significant figures.

 

Do some Google searching on significant figures.

Okay thanks I will do. I’m just drawing the schematic.