I'm totally confused and this is due Monday-
We're dealing with electrical circuits and I have to construct a circuit with resistors of 10 Ohms, 20 Ohms, 30 Ohms and 20 Ohms. The total resistance has to be 42 Ohms-Can someone direct me how to even begin to draw this-I know Parallel resistors you add sum and take the reciprocal for total and series you had them together but where do I start with this-Please help_ I'm stuck and its the weekend and this is due Monday
The 20 and 30 ohm resistors in parallel have an equivalent resistance of 12 ohms. Put the 10 and other 20 ohm resistors in series with that.
I drew my circuit but now I'm still confused-if I have a 20 V battery, how do I calculate the current through two of the resistors(say the two parallel ones of 20 and 30
Would I use the formula
V=IR
20V =I*12Ohm(which I just figured out)
20/12 = 1.67A But now I'm stuck because I don't know how to break it down into the 20 Ohm resistor and the 30 Ohm resistor
In my calculations I think I should have said V=IR
V= 20V Battery I used so
20V = I * 20 Ohm= 1A
20V = I * 30 Ohm = .67A
Your original question just asked for how to arrange the resistors to achieve a total effective resistance of 42 ohms. I told you how to do that. The total current going through each series resistor, and the battery, will be V/R = 20/42 = 0.476 Amp
The two resistors in parallel will share that current, with the lower (20 ohm) resistor getting 3/5 of it.
The reason I only asked the first part was I first wanted to understand how to construct it before I figured out the rest because I have three more sets of circuits to do so now I understand that part. I wasn't trying to mislead you-I really appreciate the help alot and can now continue with the other circuits using this as a basis-Thank you again for all your assistance
I understand that you are feeling confused about constructing an electrical circuit with specific resistors and total resistance. Don't worry, I'm here to help!
To begin, let's break down the problem and then follow a step-by-step approach.
1. Determine the required resistors: You mentioned that you need to use resistors of 10 Ohms, 20 Ohms, 30 Ohms, and 20 Ohms.
2. Understand the total resistance requirement: The total resistance of the circuit needs to be 42 Ohms.
3. Analyze the possible combinations: Since you have different resistors, you'll need to find a combination of series and parallel connections to achieve the desired total resistance.
4. Start with series connections: In a series connection, the resistors are connected one after another, so the current passes through each resistor. In this case, you can start by connecting the resistors of 30 Ohms and 10 Ohms in series. The total resistance of this combination would be the sum of the resistors: 30 Ohms + 10 Ohms = 40 Ohms.
5. Add the remaining resistors: Now, you need to add the remaining resistors (20 Ohms and 20 Ohms) to achieve the desired 42 Ohms total resistance. Since the resistors are already connected in series, you can simply connect them in parallel with the 40 Ohms combination you created before.
6. Combine resistors in parallel: In a parallel connection, the resistors share the same voltage, which means their reciprocals add up to give the reciprocal of the total resistance. To find the total resistance in a parallel combination, you can use the formula:
1/Total Resistance = 1/R1 + 1/R2 + 1/R3 + ...
In this case, plug in the values:
1/Total Resistance = 1/40 Ohms + (1/20 Ohms) + (1/20 Ohms)
1/Total Resistance = 1/40 + 1/20 + 1/20
1/Total Resistance = 1/40 + 2/40 + 2/40
1/Total Resistance = 5/40
Total Resistance = 40/5
Total Resistance = 8 Ohms
Therefore, the parallel combination of the 40 Ohms (30 Ohms + 10 Ohms) and the parallel 20 Ohms (20 Ohms + 20 Ohms) results in a total resistance of 8 Ohms.
To summarize, you can construct the required circuit by connecting a series combination of 30 Ohms and 10 Ohms, and then connect this combination in parallel with two 20 Ohms resistors. This will give you a total resistance of 8 Ohms.
I hope this explanation helps you understand the process of constructing the circuit.