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.
1.
2D -problem
A particle is moving on a frictionless, horizontal surface from ##O_{rigo}## with initial speed ## v_0 ##, as it faces the air resistance force ## F_R ##.2.
## F_R = -mαv ## (where v is a particle velocity)
## \frac {dv}{dt} + αv = 0 ##Show that:
## x(t) = \frac 1 α...
Homework Statement
This is irodov's problem #310 in electrodynamics
A long solenoid of cross-sectional radius a has a thin insulated wire ring tightly put on its winding; one half of the ring has the resistance ## \beta ## times that of the other half. The magnetic induction produced by the...
Greeting .
It is clear to me that the resistor represents a physical obstruction to the passing current I do not know how exactly it works and I will try to show what I was really interested in the diagram.
Homework Statement
1) what is the total resistance of this circuit between points A and B?
2) if the horizontal resistor was replaced with an ammeter what would it read if a 6V battery was placed between points A and B? let R = 20 ohms
Homework Equations
The Attempt at a Solution
had...
Hi friends,
My question...
At non resonance frequencies the resistance of primary is minimum or maximum?
My analysis...
There are two tuned circuit tuned to same frequency . In primary circuit at low frequency XL is low and large amount of current will flow at the inductor L1, now due to this...
Homework Statement
2. Homework Equations [/B]The Attempt at a Solution
so i was thinking i could take a look at small number of points and then generalize it but my method soon breaks down
in the diagram i have denoted the resistance of the segment beside it if there is a bracket it means...
Homework Statement
The output voltage, V_(out) (t) ‡ q(t) /C, effectively measures the charge on the capacitor as a function of time, where q(t) is an exponentially damped simple-harmonic oscillation:
a) Given that L = 0.05 mH, the square-wave frequency is 25kHz, and the ringing decays to 40%...
1. The problem statement
I did a laboratory work in which I had to find power and internal resistance. I used an ordinary battery so it's closed circuit. I did all tasks except writing a hypothesis and conclusion I can't really think of it. I don't know what to write since I just measure using...
Homework Statement
Today I did a laboratory work in which I had to find power and internal resistance. I used an ordinary battery so it's closed circuit. I did all tasks except writing a hypothesis and conclusion I can't really think of it. I don't know what to write since I just measure using...
I know that electric conductivity of metallic conductors increases with decrease in its absolute temperature(kelvin) . But is it the same for electrolytes such as water. Is cold water a better or worse conductor of electricity than warm water at same pressure and concentration.
Recently I asked why with a multimeter you should not measure the resistance of a fuse in a car while there was still power reaching the fuse but why it was ok to measure the voltage.
I was told the way resistance is measured is a small current is sent by the meter for the calculation to be...
Homework Statement
Homework EquationsThe Attempt at a Solution
Considering I- V characteristics graph, the slope for D.C. resistance is lower than that of the A.C. resistance. Now, the resistance is inverse of the corresponding slope. So, D.C. resistance should be more than A.C. resistance.
Homework Statement
Homework EquationsThe Attempt at a Solution
In the attached image the outer circular wire is represented as N . We have to find the equivalent resistance between O and N . Consider a battery of voltage V between O and N . From O there are six similar paths OA...
1. The Problem Statement
Calculate the equivalent resistance between O and the circumference. Each wire has 24 ohm resistance and the circumference has zero resistance.
2. Homework Equations
Not needed.3. Attempt at solution
I tried to use symmetry to solve this problem. I understand that...
I don't understand how this is possible.
This is a rather large transformer in a stereo system amplifier. The transformer is a simple step-down with 120V mains primary to a center-tapped secondary providing both 38V and 76V.
According to ohm's law, at 120V this thing should draw about 85 amps...
I'm having a difficult time understanding why the internal resistance of the EMF source is disregarded in this problem.
1. Homework Statement
You are asked to determine the resistance per meter of a long piece of wire. You have a battery, a voltmeter, and an ammeter. You put the leads from the...
Hello,
I was giving a random thought to Ohm's Laws and thermal dilation.
As a general rule we are told that ohmic resistors will increase their resistivity if their temperature increases. Does this take into account the fact that its dimensions will change due to thermal dilation?
This would...
Homework Statement
Homework Equations
## V=IR##
The Attempt at a Solution
This is an I-V graph so the slope must represent ##\frac{1}{R} ##
Now,
$$ R∝Temperature$$ {This is assuming that the wires are of metal}
Now , since the graph is of ##\frac{1}{R} ## , the steeper the slope the higher...
Homework Statement
I measured a battery rated at 1.5V(ε) and get 0.9V out and want to calculate the internal resistance (r). So, I model the battery as an ideal voltage source and a resistor in parallel. I know the voltmeter has a resistance of 1kΩ (R). How do I calculate the internal...
Homework Statement
In Fig. 26-5, how large must R be if the potential drop from A to B is 12 V?
(The figure has been pasted into the attached file).
The answer to this problem is 3.0 ohms. I keep trying to solve this problem but I get a wrong answer. The answer I get from my calculations does...
Homework Statement
A 60-cm long gold wire is soldered to a silver wire of the same length as shown in the diagram. If each wire is 2.00 mm in diameter, determine the equivalent resistance of the combination between A and B.
Diagram is attached.
Homework Equations
R = ρL/A
The Attempt at a...
Homework Statement
2. Homework Equations [/B]
## V = IR ##
The Attempt at a Solution
My solution:
R1,R2,R3 are in parallel and so we can find their total R
## \frac {R1×R2×R3}{R1+R2+R3} = R'##
##R' = \frac {10}{3}##
R' is in series with R4
## ∴ R= R' + R4 = \frac{10}{3} +10 =...
Homework Statement
H=I^2RT and H=(V^2)T/R.
In one case H is directly proportional to R while in the other it is not where H is the energy consumed.
Explain the apparent difference between the two cases
Homework Equations
None
The Attempt at a Solution
In the first case electricity is being...
Hi Guys
I have metabolic syndrome, amongst other things.
A friend has all the signs - sleep apnia, low testosterone, high AST, high ferritin, high blood pressure, horrid cholesterol, belly fat etc. Yet despite test after test he does not have insulin resistance. Me I am way insulin...
Homework Statement
R1= 9 Ohms R2= 17 Ohms R3= 18 Ohms
what is the total resistance of this arrangement? Express answer in ohms, correct to one decimal place.
Homework Equations
I used the Parallel circuit formula 1/r1 + r2 + r3
The Attempt at a Solution
I got 4.0 Ohms, apparently, it is...
I wasn't exactly sure which forum I should post this question in but I felt this was the most appropriate one. So if there is a more appropriate one, feel free to relocate it (whoever is responsible for that).
I wanted strictly a scientific answer to this question. How does weight affect a...
My hope is to explore [the existence of] dynamic correlation of plant tissue (leaves to start with) electrical resistance to stimuli. I've heretofore conducted experimentation reasonably sure enough of the techniques and materials I'll need that I've never posted for such advice in a public...
I wanted to ask. Since jets fly at great speed, often even supersonic, I'm curious about next things:
1) What is the relation between air resistance force and energy?
2) How does all that force resistance affect a pilot?
3) What protection do they have, if any?
4) And purely speculative...
Homework Statement
Homework EquationsThe Attempt at a Solution
[/B]
I don't understand how can current in ammeter be zero .Why is 2V battery not sending current in the right loop ?
Homework Statement
A 4 pole lap wound armature has 16 coils, each with a resistance of 0.1 ohms. Calculate the resistance of the armature?
Homework EquationsThe Attempt at a Solution
Hi there fellow members,
I'm currently doing a section of my course which deals with Electrical machines. The...
Homework Statement
Household water heaters use a 240 V rather than a 120 V source. What is the resistance of a water heater's heating element if it heats 40 gallons (151 kg) of water from 15 C to 60 C in 15 min
Homework Equations
P = IV
P = I^2R
I = dq/dt
The Attempt at a Solution
Honestly no...
Homework Statement
Homework EquationsThe Attempt at a Solution
I chose A, I understand how the resistance is the gradient, but if it is the gradient and the gradient is constant , shouldn't the resistance stay constant? (But the answer is B)
Please help~thanks a lot~
Homework Statement
Is the resistance equal to V/I at any point, or is it the gradient at that point? And Why?
Homework EquationsThe Attempt at a Solution
shouldn't it be the gradient? because it is change in V over change in I?
Thanks~
i really need help about shunt and series resistances
i just want to know if they are constant or variable ?
if they are variable what make them increase or decrease?
Homework Statement
before that, can you tell me about "current flow in this circuit" if :
A. the switch is open
B. the switch is closed
the Question is
No. 1 Calculate the resistance of R if the value of the current I in the figure is 0.50 A. ( i think it is related to no 2)
no 2. Calculate...
Homework Statement
A battery of 10 volts is connected to a resistance of 20 ohms through a variable resistance R.The amount of charge which has passed through the circuit in 4 minutes,if the variable resistance R is increased at the rate of 5ohms per minute is:
A)120 C
B)120ln2 C
C)120/ln2 C...
Homework Statement
In a potentiometer 99cm of wire of resistance 99ohms is connected with a battery of 50V and 1ohm internal resistance.Find emf of battery giving zero deflection for a length of 13cm.
Homework Equations
Sadly,the formula I know is only for ideal emfs,which states that:
If two...
Homework Statement
A battery of emf 2V and internal resistance 0.1ohm is being charged with a current of 5 ampere.
In what direction will the current flow inside the battery?What is the potential difference between the two terminals of the battery?
Homework Equations
If a battery of emf E and...
Homework Statement
A small generator of 5kW, 240V and a constant frequency is used to light up 35 bulbs in parallel, each one has (240 V, 60 W) printed on it. Calculate the resistance of each light bulb.
Homework EquationsThe Attempt at a Solution
Attempt 1[/B]
Pw = V²/R ----> R = V²/Pw...
Homework Statement
Homework EquationsThe Attempt at a Solution
[/B]
All the resistors are connected in parallel across A and B .The equivalent resistance is 1/Req= (1/R) +(1/2R) + (1/6R) + (1/12R) + ...
I tried to work with few terms and it seems the effective resistance tends to zero as...
Homework Statement
The question reads:
The following graph shows the relationship between voltage V and current I, through a particular electrical component. (The line in graph is straight, not showing properly in the photo)
What is the electrical resistance of this component when the...
Homework Statement
Prove the equation for ΔRC. (See the first attachment with the circuit schematic inside)
Homework Equations
(The equation for RC, in both attachments)
The Attempt at a Solution
You can see my attempt at a solution in the second attachment. I'm stuck at the step shown in the...
edit: The key thing I am after is why the ferrite might be responsible for the increase in resistance I measure on the coil.
Hello,
i have a coil designed to be 2.2mH and54 ohms. When an MN60 ferrite (T-ish core) is used with it, the inductance rises to 6.1mH as expected, and the resistance...
Homework Statement
In the circuit below, the RMS of the AC source is 100V, the inductive reactance is 50 ohm, the capacitive reactance is 200 ohm, the resistance is 40 ohm and the current flows in the circuit is 0.644 A. Determine the reading of the voltmeter.
Homework EquationsThe Attempt...
Hello,
I'm having a question regarding the sensors and the techniques in fluid mechanics. Since my skills are amazing in this field, here I'm asking
you questions xD
I want to measure the air pressure of this tube/pipe (P1,P2,P3). This pipe will be flushed with water and then with compressed...
Hello, I would like to ask if I have this data from impedance spectroscopy: frequency, Z(im), Z(Real), how should I calculate conductivity ? Should I use R(im) or R(re)?
Homework Statement
Find the total resistance of the circuit
Homework Equations
Parallel resistance: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ..., Series resistance: R1 + R2 + R3...
The Attempt at a Solution
The 1470 ohm resistor is parallel to the 50 ohm resistor and the 1000 ohm resistor, but there is...