What is Resistance: Definition and 1000 Discussions
The French Resistance (French: La Résistance) was a collection of French movements that fought against the Nazi German occupation of France and the collaborationist Vichy régime during the Second World War. Resistance cells were small groups of armed men and women (called the Maquis in rural areas) who, in addition to their guerrilla warfare activities, were also publishers of underground newspapers, providers of first-hand intelligence information, and maintainers of escape networks that helped Allied soldiers and airmen trapped behind enemy lines. The Resistance's men and women came from all economic levels and political leanings of French society, including émigrés, academics, students, aristocrats, conservative Roman Catholics (including priests and nuns), Protestants, Jews, Muslims, liberals, anarchists, and communists.
The French Resistance played a significant role in facilitating the Allies' rapid advance through France following the invasion of Normandy on 6 June 1944. The French Resistance provided military intelligence on the German defences known as the Atlantic Wall and on Wehrmacht deployments and orders of battle for the lesser-known invasion of Provence on 15 August. The Resistance also planned, coordinated, and executed sabotage acts on the Nazi electrical power grid, transport facilities, and telecommunications networks. The Resistance's work was politically and morally important to France both during the German occupation and decades that followed. It provided the country with an inspiring example of the patriotic fulfilment of a national imperative countering an existential threat to French nationhood. The actions of the Resistance stood in marked contrast to the collaborationism of the Vichy régime.After the Allied landings in Normandy and Provence, the paramilitary components of the Resistance were organized more formally, into a hierarchy of operational units known, collectively, as the French Forces of the Interior (FFI). Estimated at 100,000 fighters in June 1944, the FFI grew rapidly and reached approximately 400,000 by October. Although the amalgamation of the FFI was, in some cases, fraught with political difficulties, it was ultimately successful, and it allowed France to rebuild the fourth-largest army in the European theatre (1.2 million men) by VE Day in May 1945.
Hi! I am having a little trouble with a question asked by a colleague.
There’s a ball B with a certain mass M, at rest. A small ball A of mass m is moving with speed v toward M.
If m=M, and the collision is perfectly elastic and the two objects perfectly rigid, than we know that A would come...
Hello, I have a question about using the properties of conservation of angular momentum to provide mechanical resistance. Basically, I'd like to create a device that spins a disk similar to a gyroscope. The device has an external input that, depending on the configured orientation of the disk...
Homework Statement
I'm having trouble trying to find equivalent resistance. Here's a picture of some circuits I am trying to simplify (http://puu.sh/ngjMC/38160c3464.png)
For example, in circuit a, I can see that the 84 ohm and 105 ohm resistor are in series, and that can be simplified, but...
Homework Statement
[/B]
https://wcl.unr.edu/bbcswebdav/pid-634340-dt-content-rid-2875167_1/xid-2875167_1
So I am given the above image, and I am told to calculate the voltage in the circuit.
Homework Equations
V = IR
R_net = (1/R_1 + 1/R_2 + ... + 1/R_n)^-1 for parallel resistors
3. The...
I have voltage, diameter, area, and inverse area data values. How could I calculate the resistance and resistivity with these numbers? I am pretty sure resistance is R=V/I and resistivity= RA/L , so I am not sure how I can calculate resistance without an I value.
Hello, I'm working on a project and I need some assistance. I need to adjust the negative supply voltage to an integrator opamp that I use for DC offset control based upon the resistance in a voltage divider elsewhere in the design.
R12 is the trimmer resistor to adjust the CVS circuit and V5...
The microscopic Ohm's law is:
J = sigma * E
So the density in every point is proportional to the electric field in that point.
My question. This sigma is also point-dependent? So the resistor could be made of different materials and ohm's law would hold for every point differently.
Or is this...
Homework Statement
This was an experiment we did in my lab.
You're given a black box with four resistors inside, with resistances 20, 51, 100, and 200 ( k\Omega). The box has three plugs on it, labeled A, B, and C. You take your multimeter and plug into two jacks at a time and measure the...
Okay so here is my idea, not really sure how well (if at all) it would work but I am wondering if it would be possible (assuming battery technology is good enough) to ionise air in front of a formula 1 car (or plane or whatever) giving it a charge (like the way lightning works) , then creating...
Simple as that, I've uploaded the image. I don't really care about the exact value, I would prefer just to know the method. So how would I find the equivalent resistance between A and B? Note the component in the middle is a constant current source.
Wondering the best way to go about calculating the ability of a silicone wafer to withstand impact. Wanting to possibly use a small pc as a fracture barrier to indicate that a part was dropped and may potentially be damaged. Need it to handle 20G. Alternative mat'l suggestions would be...
Homework Statement
Find the equivalent resistance between AB.
Homework EquationsThe Attempt at a Solution
I could not find any Wheatstone bridge or series parallel combination. Should I use star delta transformation ? If yes, how exactly should I use it ?
Homework Statement
The resistance of a bobbinin 0 grades celcius is 3.35 ohm. What is its resistance in 50 grades celcius? thermal constant=0.0037
Homework Equations
R1=R0[1+alpha(t-t0)]
The Attempt at a Solution
Using this formula
R1=3.35[1+0.0037(50-0)]=3.35*1.185=3.96975, but the answer in...
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...
Homework Statement
When two same lamps are connected with the same battery. Their lighting will be greater when they are connected in series or parallel?
Homework Equations
Series U=U1+U2+U3+...
I=I1=I2=I3...
Parallel U=U1=U2=U3...
I=I1+I2+I3+...
The Attempt at a Solution
The answer is when...
Homework Statement
If the diameter of a wire (conductor) is dimidiated , then its resistance:
A Remains unchangable
B is diminiated
C Becomes two times greater
D Becomes 4 times greater
Homework Equations
R=constant*length/Surface
The Attempt at a Solution
Cross sectional area=pi r^2=pi...
Homework Statement
The resistance of a wire (conductor) in cylindrical form is:
A Disproportional with the length of the wire (conductor)
B Disproportional with the square of the wire (conductor) section
C Proportional with the square of the length of the wire (conductor)
D Proportional with...
Homework Statement
The carriage and its passengers start at rest at A. At B, the bottom of the ride, the maximum speed of the carriage is 20ms-1. The vertical distance between A and B is 110m. The length of the track between A and B is 510m. The mass of the carriage and the passengers is...
The formula to find the total resistance in a parallel circuit is 1/R=1/R1+1/R2+1/R3, but wouldn't it be easier to use R=1/(1/R1+1/R2+1/R3)? I've only ever seen the equation written like that once before, and I'm wondering if there's a reason as to why it's never really used?
Disclaimer: I'm not sure if this is the correct forum.
An ideal conductor (ideal = no resistance) is essentially taking the electric field at one terminal and connecting it to the other terminal. Charge moves when it is in an electric field, electric field strength is in Volts per meter, or...
I was told that for resistors connected in series (whatever the equivalent resistance be) the current flowing through a circuit will be a constant
Say i had 'n' number of resistors in series connected to say a battery such that the equivalent resistance was equal to that of an insulator, would i...
Homework Statement
Q4) Calculate the thermal resistance of the heat sink required for the regulator of Q3 above given the information below [from the datasheet] and the data in the table.
Q3 FIGURE 2 shows an adjustable voltage regulator using the LT1083*. The LT1083 develops a 1.25V reference...
Speaking just of long straight wires, not loops, coils or solenoids.
Ideal wires have no resistance. Of course they would have no capacitance. And real wires have some very small amount of inductance, no?
Firstly, would an ideal wire have some ideal nonzero inductance? Why/why not? After all...
Homework Statement
When the resistor is R1, in the circle there is the intensity I1 and when the resistor is R2, the intensity becomes I2.Find emf and the inner resistance.[/B]
Homework Equations
I=emf/R+r
The Attempt at a Solution
I1=efm/R1+r
I2=efm/R2+r
efm is equal
I1*(R1+r)=I2(R2+r)...
Homework Statement
A battery is connected with a resistor R1=4 om and then it is replaced with the resistance 9 om. In both cases the heat released in the same time is the same. Find the inner resistor of the battery.
Homework Equations
Q=UIt (U-tension; I-intensity, t-time)
I=e.m.f/R+r
The...
The question in textbook:-
A 4uF capacitor is charged by connecting it to 200V supply.It is then connected to an uncharged 2uF capacitor.How much electrostatic energy of the first capacitor is lost in form of heat and electromagnetic radiation?
My question is that why the energy must be lost...
Homework Statement
A 5V battery rated at 1800mAh has a soucre resistance of 10 Ohms. What is the maximum power that can be extracted from the battery?
Homework EquationsThe Attempt at a Solution
I understand that had the battery not had any source resistance then the power out would have been...
Homework Statement
https://z-1-scontent-sin1-1.xx.fbcdn.net/hphotos-xtf1/v/t34.0-12/12435980_942112312550457_1708451532_n.jpg?oh=b29a5e9b2ff96bbf0e11932d081eb25e&oe=568A9B79 [/B]
We need to find the equivalent resistance along A to B ie AB
Homework Equations
R=(1/R1 + 1/R2+...+1/Rn)^-1 ...
Hi.
I am re-engineering a 40+ year old carburettor design. The current throttle slide has stress raiser flaws and is the same material as the mixing chamber that it slide interfaces with. The prototype slides were printed in ABS for fitment trials. The functional trials used Acetal allowing for...
Homework Statement : [/B]
Given a voltage regulator with 6.8V Zener diode, input voltage range of 15-20V and load current range 5mA-20mA. Calculate the series resistance R for the regulator.Homework Equations : [/B]
Applying KVL and no load situation, we get R = (V - Vz)/Iz where V is the...
Homework Statement
A 2000 kg boat's motor can exert a force of 6000N. The water provides a resistive force of 2000N. What is the magnitude of the acceleration.
Homework EquationsThe Attempt at a Solution
that the boat has a 4000 N total force going foward
I'm trying to write a program to calculate the trajectory of a projectile with air resistance. I've made the following function which calculates the position of the particle based on a given launch angle and initial velocity:
def traj_fr(angle, v0): #function that computes...
Hi guys.
I'm looking into the modelling of a transmission line model (TLM) and feel that I'm understanding it fairly well. Although, one parameter keeps popping up with very little explanation as to what it actually is.
It seems that to characterize contact resistance for a e.g. GaAs TLM with...
Homework Statement
R = 10 Ohms
Homework Equations
Req = (1/R1 + 1/R2 + ... )(-1)
Req = R1 + R2 + ...
The Attempt at a Solution
I honestly don't even know where to start...
The obvious thing to do is
4R + 2R = 6R
That's pretty much all I can come up with that makes sense... Any help?
Homework Statement http://imgur.com/uLZdBJC
27. The switch has been closed for
about 1 h. It is then opened at the time defined as t 0 s.
a. Determine the time required for the current iL to drop to
10 μA.
b. Find the voltage VL at t 10μs
c. Calculate VL at t 5tau.
Homework Equations
So I...
Hi guys.
I'm looking into the modelling of a transmission line model (TLM) and feel that I'm understanding it fairly well. Although, one parameter keeps popping up with very little explanation as to what it actually is.
It seems that to characterize contact resistance for a e.g. GaAs TLM with...
Suppose that there is a positively charged particle and a negatively charged particle in free space. The electric field of the positive charge causes a difference in potential between the position of the negatively charged particle and the positively charged particle. This, causes the negatively...
Hello. The measurement of electrical resistance as a function of the superconductor's temperature yields fundamental insights into its properties. The Critical Temperature, Critical Current Density, and the Critical Magnetic Field, can all be obtained through variations of a basic experiment.
I...
Homework Statement
In the interval between the freezing point (ice point) of water and 700.0deg-C, a platinum resistance thermometer is to be used for interpolating temperatures from 0 °C to the melting point of zinc, 692.666 K. The temperature, in Celcius or Centigrade, is given by a formula...
I wanted to do a science experiment and it is very important that i learn the electrical resistance of carbon dioxide. From what i would guess, this may be wrong, but carbon dioxide and the atmosphere on Earth probably have a similar electric resistance due to the fact carbon dioxide already...
1. The problem
Given a circuit with a 30V source and five resistors. The circuit can be drawn as two boxes. Resistor 1 (R1 = 300ohm) is in series with the source. R2 (300ohm) in the middle of the two boxes, and the remaining resistors (550 ohm) in series at the other side of the box.
The...
Homework Statement
The two voltmeters have very large resistance, the 3 ampere meter have resistance of ##0.5\Omega## each one.
##V_1## show twice as much voltage as ##V_2##, ##A_1## shows ##0.4A## and ##A_2=A_3=0A##
a. Find ##R_2##
b. Find the internal resistance of the battery
Homework...
I'm a games programmer working on a (simple, so far) physics engine for a driving game. Right now I'm interested in acceleration, and in particular trying to estimate the forces that go into it. I've got basic data for a bunch of cars (0-60 time, 0-100 time, top speed, mass) and a brute-force...
From my understanding, transformers allow electricity to travel long distances with minimal energy loss because they initially use a step-up transformer which reduces the current (which reduces the heat loss and hence energy loss). However, I do not understand how a step-up transformer manages...
Homework Statement
What is the Total resistance in Question 38.
Homework EquationsThe Attempt at a Solution
I tried drawing the circuit again splitting up the series and parallel but i got the wrong answer. The answer is 92. Like i know that the 60 is parallen to 15 and the 15 is parallel to...
Homework Statement
Problem in photo...
Homework Equations
Don't know... Cause velocity ( m/s) isn't acceleration and therefore you can't find Fnet... So I don't know
The Attempt at a Solution
Does it have anything to do with finding Fn than multiplying that?
Hello,
A diode is represented by an EMF equal to the electric field in depletion zone plus a resistance. This resistance is obtained from the I/U characteristic of a diode. My question is, this resistance is due to what? The resistivity of P and N junctions or because in forward bias case...
Can someone explain three wire and four wire RTD circuits in terms of how the lead resistances affect the voltage output
##V_o = \frac{R_3 V_s}{R_2 + R_3} - \frac{R_4 V_s}{R_1 + R_4}##
Also, in the case of a three wire, what is the purpose of Lead C?
Homework Statement
How to calculate the value of total resistance RT in the shown circuit?
Homework EquationsThe Attempt at a Solution
I used Kirchhoff` first law: i1+i2=I where i1, i2 and I are the current passing through R1, R2 and the total current in the circuit, respectively.
similarly...
Homework Statement
In the fig all resistors have resistance R. If pd of V is applied across AB.
1)What is the outcome of joining C and D
2)Whats is the pd across CO
3)what is the resistance across A and B
4)What is the resistance across AO
Homework Equations
V=IR
1/∑R=1/R1 +1/R2
The Attempt...