A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators.
Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity.
Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. Resistors are also implemented within integrated circuits.
The electrical function of a resistor is specified by its resistance: common commercial resistors are manufactured over a range of more than nine orders of magnitude. The nominal value of the resistance falls within the manufacturing tolerance, indicated on the component.
The question is to find the resistance between points A and F.
I understand that the resistor between OC can be removed. From this point onwards, resistor OC has been removed. Let the far right point of the diagram, where i5 and i7 exit from, be B.
Is it possible to detach the remaining...
I already did part a and got the correct answer of 4.8 microC. However, I am unsure how to approach part b, where the switch is closed and apparently the two capacitors end up with different charges. For part b, since there is a path between the two capacitors, I don't know if I am able to...
Homework Statement
The circuit is the one in "Fig.4"
I need to calculate equivalent resistance between A and B. This is what I've tried:
I think that the first resistor is shorted by that wire connected between A and E. Their answer looks like this, in fig 2.2.1. I'm not sure if their...
I've seen answers saying that electricity takes path of least resistance, I know this and there is no need to explain this for me.
A forum's answer told me that the electrons initially flow through to the path with resistance and eventually becomes congested (redirecting the remaining electrons...
Homework Statement
So I need to find the equivalent resistance for the following RC circuit to calculate the time constant, but I got stuck in terms of finding out the equivalent resistance.
Homework Equations
V = IR
The Attempt at a Solution
So the thing I am not sure on is how do you...
Could somebody help me out with this combination circuit? The answer that I get is 62K but that is not one of the answers. At first, I thought the 10kohm and 20kohm wherein series and the other side as well. Then I thought they are all in parallel because of the different current flow they all...
Hey guys, in the picture below, the current flowing through R1 is the same flowing through R3 right? And hence we have R1 and R3 in series?
In this second picture R2 is going to cancel out because apparently that's what happens when you have a branch containing components parallel with a wire...
Homework Statement
Work out the total resistance of a combined circuit.
https://gyazo.com/935b96ff63689e2bff852f29ea48bf90 - picture of circuit layout
Homework Equations
Rt=R1+R2+Rn...
R=V/I
1/RT=1/R1+1/R2+1/Rn...
The Attempt at a Solution
RT=R1+R2 =100+150=250Ω for the resistors in series...
So I have two formulas for calculating voltage drop. The first is: Vdrop = Vin * R1 / ( R1 + R2...). This let's me calculate the voltage drop on the first resistor in a series of 2 resistors. You can also extend this to more resistors in series just by summing all the resistors. However, I do...
Hi
I am to calculate Rab of the circuit and I have no idea on how to approach this problem. It would have been all nice and eaasy if it weren't for the vertival 30 ohm resistor. Because of this I'm in a dark spot. I will appreciate any help.
Homework Statement
I'm just really lost on this topic and honestly don't have too much of an idea.
(a) Using Kirchoff's loop rule, find the differential equation satisfied by the charge q(t).
(b) Verify that q(t) = q_max e^-(a/t) cos(ωt) satisfies the differential equation for particular...
Homework Statement
(see my attached photo to better understand where I am coming from!)
So after some research, I've discovered that the current at different points in a simple series circuit is supposed to be the same value, and that the voltage is supposed to be different values.
I...
shmoop
Thread
electricity
electricity and magnetism
resistor
resistors
series circuit
Hi guys!
(see my attached photo to better understand where I am coming from!)
So after some research, I've discovered that the current at different points in a simple series circuit is supposed to be the same value, and that the voltage is supposed to be different values.
I performed a lab on...
shmoop
Thread
electricity
electricity and magnetism
resistor
resistors
series circuit
Homework Statement
You are tasked with designing an electrical circuit with a motor, a battery, and several 1ohm and 2ohm resistors. The motor is designed to run at a current of 20A and a voltage of 10V, but your battery supplies 15 V. The motor can then lift a 4kg mass 2.25 meters in...
Homework Statement
There is a figure, I'll try my best to draw/describe.
1. All three resisters are in parallel
___R____
!___R____!
!___R____ !
2. 2 resisters are parallel and one in series, after the parallel (ignore the dots)
___R___
... _____R___
!___R___ !
3. 2...
Homework Statement
I am confused what to do but I have to find the current through the battery:
Homework Equations
V=IR
The Attempt at a Solution
I decided to find the equivalent resistance and do V/R = I using the 14V, but I believe my Req is wrong. What is throwing me off is the...
Could I combine the two resistors together in parallel to make an equivalent resistor, and then use that equivalent resistor in series with the capacitor?
It would be great if there was some rule of thumb that I can use to know what I can make into an equivalent resistor/capacitor down the line...
Homework Statement
finding the resistor and current which is following through the circuit[/B]
Homework Equations
kirchhoff law
The Attempt at a Solution
almost as fig 1 ( 9v=3.458 mA and 12v=11.122 mA)
fig 2 (9v=1.472 mA and 12v=12.882 mA) i3=2.48 mA
Homework Statement
From the circuit diagram ( http://postimg.org/image/lldnr7mf7/ ) calculate the net charge flown through the capacitor 2.
Homework Equations
3. The Attempt at a Solution [/B]
I actually don't need to solve the full problem as i understand how, what i have trouble with is the...
Homework Statement
Solve this circuit:
a) Mark all currents
b) Write a system of equations allowing you to solve for the currents
2. The attempt at a solution
Part a) in attachment.
Part b)
\epsilon_1 = i_1 r_1 + (i_1 + i_2 + i_3) R
\epsilon_2 = i_2 r_2 + (i_1 + i_2 + i_3) R
\epsilon_3...
Homework Statement
https://s10.postimg.org/lb6n94ua1/20161007_190700.jpg
Homework Equations
V=IR
The Attempt at a Solution
So far I haven't had any problems finding the Req. However, I am having trouble with the VIR chart. Can anyone confirm whether or not I did it correctly. My thought...
The goal of this problem is to find the equivalent resistance of all the resistors. Each resistor shown in the image has a conductance of 1 mS which I believe is equal to 1000 ohms. I attached a picture of the circuit diagram in which I show some of my work in order to convey my erroneous...
Homework Statement
A 60 W lightbulb and a 100 W lightbulb are placed one after another ( in series, the 60 W battery closer to the positive terminal of the battery) in a circuit. The battery's emf is large enough that both bulbs are glowing. Which is the true statement?
A. The 60 W bulb is...
Homework Statement
[/B]
Three resistors are connected to a real battery. The open circuit voltage of the battery is 4.5 Volts. The voltage across the 5 Ohm resistor is 2.5 Volts.
A) What is the voltage across battery terminals?
B) What is the internal resistance of the battery?
Here's a...
A 5μF capacitor is connected in parallel with a 2MΩ resistor and the combination is then connected in series with a 1MΩ resistor through a switch to a 12V battery. Find the time taken for the voltage across the capacitor to rise from zero initial value to 2V after the switch is closed.
From...
Hi, I have been at this problem for days and I can't seem to see what I am doing wrong.
Here is the circuit layout along with my work
As you can see I am running into problem getting values of current that do not add up equal to zero. My professor has never discussed how adding a wire like...
Im reading this stack exchange question:
http://electronics.stackexchange.com/questions/28897/how-to-choose-value-of-resistor-in-voltage-divider
So there is a 5V circuit with 2-100 Ohm resistors that yields a voltage drop across the divide of 2.5V. The current through the circuit is 25mA...
Homework Statement
A circuit is constructed with five resistors and one real battery as shown above right. We model. The real battery as an ideal emf V = 12 V in series with an internal resistance r as shown above left. The values for the resistors are: R1 = R3 = 57 Ω, R4 = R5 = 75 Ω and R2 =...
Homework Statement
http://i.gyazo.com/c6b73ca3a53b7d36bce59a0aa5009d27.png
Homework Equations
Kirchhoff's Current and Voltage Laws, Resistors in parallel and in Series.
The Attempt at a Solution
The main thing confusing me is the diagonal 6 Ohms, not too sure what it is parallel too and how...
Homework Statement
What is the voltage drop across the 1000 Ohm resistor when capacitor is fully charged?
Homework Equations
V(t) = {V_i}*e^{-t/RC} = {V_i}*e^{-t/Tau}
The Attempt at a Solution
In RC circuit experiment, initial is 9V and final is 2V. The voltage drop should be difference...
Homework Statement
If you measure the resistance of the three lightbulbs (independently) and get the following values. What is the equivalent total resistance of the circuit, and it’s uncertainty.
R_1 = (50 \pm 7) \Omega, \ \ R_2 = (720 \pm 30) \Omega, \ \ R_3 = 140 \pm 20) \Omega
Now you...
Homework Statement
The ammeter reads 5.0A. Find I1, I2, and ε
Homework Equations
ΔV=IR
The Attempt at a Solution
I've never dealt with ammeters before so I'm very confused.
To start, I tried breaking this into loops, and then used Kirchhoff's Law.
I started with the left side, since I...
Homework Statement
Assuming R = R' in the network shown above, determine the net resistance between the points a and c. Express your answer as a number times R.
b. Assuming R = R', determine the net resistance between the points a and b.
c. Now suppose R' = 2.5R, and find the net resistance...
If there is only one resistor, the voltage drop is equal to the potential of the positive terminal. The voltage drop across more than one resistor is directly proportional to the value of each resistor. But the total drop in potential difference must be equal to the potential of the positive...
Homework Statement
NOTE: Image uploaded with thread shows problem in clearest possible form.
V = (45v)sin(80[pi] t)
Resistors 1 and 2 = 50 Ohms
Inductor 1 = 20 mH
Inductor 2 = 2.5 mH
Capacitor = 50 uF
a) Find the power dissipated by each resistor.
b) At what frequency will both resistors...
Homework Statement
In the circuit shown, a student mistakenly connects a perfect ammeter(i.e. One of negligible resistance), in parallel with one of two identical resistors. The ammeter reads 0.40A.
What would the reading have been if he had correctly connected the ammeter in series with the...
Homework Statement
Picture provided.
The current going through the resistor R1 in the figure does not change whether the two switches S1 and S2 are both open or both closed.
The resistances are R1 = 14.00 Ω, R2 = 142.00 Ω, and R3 = 24.00 Ω. The voltage is V = 11 V.
With this information, what...
Homework Statement
The current going through the resistor R1 in the figure does not change whether the two switches S1 and S2 are both open or both closed. The resistances are R1 = 70.00 Ω, R2 = 50.00 Ω, and R3 = 62.00 Ω. The voltage is V = 15 V. With this information, what is the value of...
Homework Statement
Ignore the internal resistance of the battery and assume it is merely a battery. Calculate the equivalent resistance of the circuit.
Homework Equations
1/Req = 1/R + 1/R ... (parallel)
Req = R + R ... (series)
The Attempt at a Solution
I know this is fairly simple but I...
Homework Statement
[/B]
R1 = 42 Ω
R2 = 124 Ω
R3 = 119 Ω
R4 = 105 Ω
Rx = ?
I4 = O A
Homework Equations
R = IV
V = V1 = V2 for parallel Resistors
Iequiv = I1 +I2 for parallel Resistors
Vequiv = V1+V2 for series Resistors
Iequiv = I1= I2 for series Resistors
The Attempt at a Solution
I have...
Homework Statement
There is a circuit with a battery of voltage V and resistor R, then splits into two branches one with a capacitor C, and one with a resistor 2R.
The answers for the questions can only depend on R, C, V, and t.
When a switch only allows current to flow through the capacitor...
I am confused about the concept of a power dissipation limit for a resistor. Basically for a resistor the product of the current through it and the potential across it should not exceed 0.25 watt otherwise it starts to heat up and act in a non-linear fashion. Is this value just a constant or is...
The following circuit has been modeled using some modelling software (Micro-Cap 11).
I was wondering why current is only shown at the source and not in R1, R_Unknown and R3.
I know current is meant to be the same in series although I am confused by the effects of the resistors.
(This is not a...
Homework Statement
Look at the circuit given in figure 1. Solve for the three currents, I1,I2,I3.
Homework Equations
KVL: Sum of voltages in a closed loop equals zero
KCL: Sum of currents entering a junction equals the sum of currents exiting a junction
Ohm's Law: V=IR
NOTE: Nodal analysis...
I feel like have a chicken and egg type of problem regarding internal resistences because of the following problem:
The voltage across a battery with internal resistence is given by the equation
EMF-Ir=V
Given the voltage across the battery then the voltage in the circuit is
V=IR
So, if I have...
1. A) Find the Effective resistance of a tree of resistors that bifurcates 3 times.
B) Find the effective resistance of a tree of infinite resistors. (if the tree below went on to infinity)
Homework Equations
Ohm's Law
The Attempt at a Solution
I have no idea how to start this. There was no...