Suppose that the resistor arrangement in the figure(Figure 1) is connected to a

Question

Suppose that the resistor arrangement in the figure(Figure 1) is connected to a 11 V battery.

1) What will be the current in each resistor?

2) What will be the voltage drop across each resistor?

What will be the current in each resistor? Item 17 Express your answers using two significant figures separated by commas Suppose that the resistor arrangement in the figure(Figure 1) is connected to a 11 V battery 11, 12, I3, I4 Submit My Answers Give Up Part B What will be the voltage drop across each resistor? Express your answers using two significant figures separated by commas i Figure 1 of 1 R1 = 2.0 Submit My Answers Give Up R2 = 2.0 R4 = 2.0 Part C Ra=2.0 What will be the total power delivered? Express your answer using two significant figures

Explanation / Answer

Series resisters add. Rt = R1 + R2
Series resistors only have 1 end connected to the next resistor.

Parallel resistors add like fractions 1/Rt = 1/r1 + 1/r2
Parallel resistors have both ends connected to the next resistor.

Step One
=======
Find the total resistance of R1 and R2. They are in series. Which formula do you use and how do you know they are in series?

That's right. They are in series so use
Rt1 = R1 + R2
Rt1 = 2 + 2 = 4 ohms.

Step Two
=======
Find the resistors that are in parallel

If you know the extended formula you could find the total resistance right now. If you don't, you have to do it one step at a time. I'll assume you can figure out how to put 3 resistors in parallel. Which formula do you use?

here it is.
1/rt = 1/Rt1 + 1/R3 + 1 / R4
1/rt = 1/4 + 1/2 + 1/2
1/rt = 1 + 1/4 = 5/4 I think it is better to use 5/4 rather than 1.25

rt = 1//5/4 = 4/5 = 0.8


Step Three
=========
Find the voltage drop across R3 and R4.

The voltage drop across R3 and R4 is 11 volts. Those two resistors see the entire voltage. If you are having trouble conceptulizing this, think of the light bulbs in your house. If one burns out, they don't disable all the other light bulbs. That's the way parallel circuits work.

Step Four
=======
Find the current in Rt1
Rt1 = 4 ohms
V = 12 volts

V = I * R
12 = I * 4
I = 11 / 4 = 2.75 amps.

Step Five
=======
Find the voltage drop R1 and R2.

Now

you can see that since the resistances are the same, the voltage drop must be the same in both of them. 11/2 will give you your answer. However you should know how to do it formally because if you don't, you won't see how to do it if the resistances are different.

R = 2 ohms
E = ????
I = 2.75 amps

E = I * R = 2 * 2.75 = 5.5, which is just what you would expect. Both resistors experience a voltage drop of 5.5 volts, just what your intuition told you.


Step six
======
Find the current in R3 and R4.
R3 and R4 both will have the same current because their values are the same, but again, you have to know how to do this formally in case the values are different.

R = 2 ohms
E = 11 volts
E = I * R
11 = I * 2
I = 5.5 amps

Summary
=======
The current in R1 and R2 = is 2.75 amps for both.
The current in R3 and R4 = 5.5 amps.

The voltage drop across R1 and R2 = 5.5 volts
The voltage drop across R3 and R4 = 11 volts.

Step Seven
=========
Determine the total power delivered.
There are all kinds of ways to do this. I will do it by using the total resistance, but there are other ways.

R = 0.8 ohms [remember that 0.8? Where did we get it?]
V = 11 volts.

P = E * I = E^2 / R
P = 11*11 / 0..8
P =151.25 watts and that is an awful lot of power to be delivered by 11 volts,

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.