Composite materials consist of various components such as moist wood ,how will the internal resistance of this material behave?
If I want to study the resistance of composite materials, which topic should I study?
Hi,
I understand mathematically why using low resistance results in a greater heating effect. Could someone give an intuitive and microscopic picture of why the current contributes more to a greater power dissipation by the resistor rather than the resistance contribution to the power...
Hi there,
I have modelled with MAXSURF a few variations of a prehistoric logboat in order to test a few theories. Now, I am trying to look at resistance-performance over a range of speed. To do so, I need to include a constant drag coefficient without knowing the drag force and velocity (both...
(i) Dividing the rod into thicknesses of dx we get discs of area A with lengths=dx so using (****) we have the resistance of a typical disc (between point x' and x'+dx) as:
(1) ##R(x'dx)=\frac{dx}{g(x)A}##
(ii) Using (1) and (*) and the integrating from a to b of the entire rod we get...
Given that they're all on the same branch, I had assumed that they were in series with one another. But with the middle resistor having being on the middle of three branches, it looks parallel.
Like I said, I have a feeling it's in series (making the answer 3R).
This question is from a past...
Hi! I've been struggling with this.
Original exercise here: Find the value of Iy when R=0. And the value of Vx when R is infinite.
For the first part of the question I did this since R=0:
I've tried to solve this circuit and I get that Iy and I5 are 0 A, and this can't be possible since Iy...
I was reading The Feynman Lectures on physics http://www.feynmanlectures.caltech.edu/I_23.html chapter 23, section 4. In it he derives the equation for current when inductor, resistor and capacitor is connected in series with an alternating voltage source, he derives this equation:-...
Let's assume a 2:1 transformer which has a 100V Source connected on the primary circuit and has no/negligible resistance, on the secondary circuit a 5 Ohms resistor is connected. Using the 'Impedance Transfer/Reflection' method, the primary circuit would act as if there was a 25 Ohms resistor...
[ mentor note: post adjusted to conform to hw template and some spellings fixed ]
1. The Problem
I have some few questions that connect voltage, current and resistance.
Imagine that we have a circuit that consists of a battery (5V), 2 resistors. Now once we close the circuit, battery would do...
1. Homework Statement
1. A 2.01 uFcapacitor that is initially uncharged is connected in series with a 6.51 kΩ resistor and an emf source with 74.6 V and negligible internal resistance. The circuit is completed at t = 0.
a) Just after the circuit is completed, what is the rate at which...
Imagine you have a vertical pressure head 2m tall with water flowing down to height 0m and emptying. Through this length we have 3 identical tubes of resistance R and length L. Assuming I know the volumetric flow rate(Q) as a function of height, how can I calculate the resistance of each tube...
I'm currently in a undergrad level course of eletromagnetism and my professor found it useful to remember quickly of some relationships that we see in high scool, among them power waste.
I got the formulas, since they're simple and are direct derivated from the definitions of electric current...
i have a drawing of a circuit that converts a signal in range [-5,5] V to a range [0,1.2]V .
i wish to understand how it works..
i have basic knowledge of electricity as an undergraduate in general physics but a bit rusty , thus i am here looking for answers...
Is ohmic resistance a "necessary evil" in order for transistors to be able to function as logic gates?
I mean, I have seen some circuits for the NAND gate in RTL and TTL and they both seem to involve ohmic resistances. Can we make a super conducting NAND gate that will have total ohmic...
1. Homework Statement
translation ; we know the values of
R1 = 1 ohm
R2= 2 ohm
R3= 6 ohm
R4= 2 ohm
R5= 4 ohm
R6= 4 ohm
we can also see the voltmeter reading a potential difference value of 8 volts , and...
I was getting a bit confused with Ohm's law, and the relationship between the current, resistance and voltage/potential difference?
From my understanding, current and voltage both increase or decrease together, while current and resistance do the opposite?
I was then wondering if there was any...
I'm not really sure if this is even scientific but while calculating how much energy is stored in electromagnetic coils and capacitors, pretty much the same formula is used:
For electromagnetic coils it's U=0.5LI2
For capacitors it's U=0.5CV2
Why I think they're the same is that in a sense L to...
1. Homework Statement
I'm asked to find a combination of resistors (parallel and/or series) that uses resistors of 25 Ω, 100 Ω, 50 Ω, and 50 Ω. They should add up to give a total resistance of 62.5 Ω.
2. Homework Equations
Req for parallel = 1/R1 + 1/R2 + ...
Req for series = R1 + R2 + ...
1. Homework Statement
I'm asked to find the voltage, current, and resistance through each resistor in the given circuit.
2. Homework Equations
Req for parallel = 1/R1 + 1/R2 + ...
Req for series = R1 + R2 + ...
3. The Attempt at a Solution
First, I want to find the total resistance in...
< Mentor Note -- thread moved to HH from the technical forums, so no HH Template is shown >
a) Using the Yenka (or similar) simulator, you are required to build an RS flip-flop using 2 NAND gates, switches, LEDs and 330Ω resistors. Test the circuit and prove its correct operation against the...
1. Homework Statement
Coaxial cable has radius a of copper core and radius b of copper shield. Between there is an isolator with specific resistance ζ. What is the resistance of this cable with length L between the core and the shield?
2. Homework Equations
First, I tried to solve this like...
A circuit contains a 7.5V d.c power supply and three resistors. The total resistance of the circuit is 30 ohms. Why will the largest current in the 18 ohm resistor? As far as I know is that the smallest current will be in 60 ohm resistor because it has the maximum resistance. Please explain...
Hi! I'm working on a project in which a small microcontroller with a max. analog input of 5v takes readings from multiple sensors. I would like to make this input window a bit more versatile, and turned to voltage dividers as a solution. 'Problem is, I'm having a bit of trouble understanding how...
1. Homework Statement
I need to calculate the specific conductivity k and the resistance R of a cell containitng 0.01 M HCl and 0.1 M acetic acid (HAc).
I know the molar conductivity of HAc: Λm = k/c = 5.14 cm2S/mol.
I also know Ka (HAc) = 1.795 *10-5.
I know the cell constant Kcell = R*k =...
1. Homework Statement
A metal rod can slide on a rail without any friction in the presence of uniform magnetic field of B=1T which is perpendicular to the plane of the paper.The distance between the tracks is d=0.1m and the resistance given is R=0.1 ohm.The resistance of the rail is negligible...
1. Homework Statement
if someone could help me with this it would be much appreciated. In physics, I used a 98Ω resistor in a series circuit and measured the current and voltage output from battery, using the current and voltage I calculated the resistance. I=0.0094A V=1 Rt=1/0.0094=106.38Ω...
1. Homework Statement
(Is the image read-able now? )
The fig 1 shows the relationship between voltage and current when voltage is applied to a certain light bulb.
Next, in fig 2, the bulb is connected in series with a 12-V battery and a 5 ohm resistor.
Question : what is the amount of power...
I was looking for any credible sources who could reveal the resistance of a normal tungsten filament bulb at room temp 20 C? I heard its cold resistance is about 9.5ohms. Is that the resistance at rtp? Thanks a lot in advance!!!!
Hello!
I've took a course about Electrical circuits and Networks at the university, and i found out a problem which is uploaded by my professor, and i think he made a mistake!
this is the solution
i think that the equivalent resistances are wrong (beside Rab), for example if you look at...