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.
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...
Homework Statement
I am not sure how to calculate the resistance of the circuit and each resistor using voltage and current. I know how to work the resistance out in series and parallel but am 100% how to work it out in combined.
Homework Equations
R=V/I, 1/Rt=1/R1+1/R2
The Attempt at a...
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...
Homework Statement
If you have a 100 W bulb and a 60 W bulb connected to separate electrical outlets, which will be brighter? Which has more resistance? Explain.
2. Necessary formulas
P=IV and (maybe?) I=V/R
3. The Attempt at a Solution
I know for sure the 100 W bulb is brighter. However...
Homework Statement
Estimate the rolling resistance force for a 75gram vehicle with axle friction coefficient of 0.2 if the wheel is 40mm diameter and the axle 2mm diameter.
I am having trouble with applying the axle friction coefficient. I could not find a similar problem online.
Basically...
Homework Statement
Why is my calculated total resistance of the circuit higher than the resistor used in series and the theoretical total resistance? In a series circuit I used a 100Ω resistor and measured the current at 1.0v intervals from 1.0-5.0v.
At 1.0v the current was 8.70mA using a 100Ω...
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, everyone
i always had this question in mind, and also tried to look for answers on the web,
but alas! i can't seem to find definite answer!
i am currently making a fountainpen nib with a carbide point.
the traditional material for fountainpen tipping is iridium + osmium alloy...
Homework Statement
Homework EquationsThe Attempt at a Solution
The original question given above has been correctly answered by me .The correct option is 2) .
Thinking more about this problem made me wonder if there could be a combination of L1,L2,L3(different from that given in the...
Homework Statement
Find the equivalent resistance of this circuit between points a and b
https://imgur.com/a/LWcIC
Homework Equations
The Attempt at a Solution
I am not sure how to complete this problem without any variables. I tried replacing the numbers with the variables which is what I...
Homework Statement
problem in title:Homework Equations 1/Rtotal = 1/r1 + 1/r2...[/B]The Attempt at a Solution
[/B]
I can get it down to 4 resistors...but the one's I have circled I don't know how they behave. I just need a little kick in the right direction lol. Thank you in advance!
Homework Statement
Hi Physicsforum, this is my first post so apology if I make unclear equation. I try to solve this question by pluging t0 as temp. at Valley and t as temp. at Antartitca directly as oppose to setting separate equation. I got different answer than the solution said
While...
Hi there,
I am new here so please don't be too hard on me yet and move this post if i placed it in the wrong forum.
I am developing a little experiment game and i want the train to drive using real physics, but I am really bad at physics.
So my question is is how do I calculate the friction of...
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...
Homework Statement
Part C of the following problem
http://www.chegg.com/homework-help/questions-and-answers/problem-1-find-equivalent-resistance-rab-circuits-figp36-q8156743
2. Homework Equations The Attempt at a Solution
Hi, to solve this problem, first i tried to ignore the two resistors...
Homework Statement
I have found a differential equation that models a non-linear pendulum with air resistance, and now I have data. I've looked at the following site for guidance on how to analyse the data. It compares the motion of a damped spring, and compares it to the motion of a damped...
Students seeking “deeper” understanding of basic electricity, frequently come with one of the following misconceptions.
1. Electrons are like balls, they start with potential energy and gain kinetic energy. They deliver their energy to the far end of the wire by filling a bucket.
2...
Hi all,
Sorry in advance if my questions are stupid and the answers are obvious.
I can see from P=VI why a high power appliance requires more current to function. However looking at ohms law and I=V/R it’s telling me that greater resistance will lead to less current. I've always figured that...
Homework Statement
An automobile battery has a terminal voltage of 12.8 V with no load. When the starting motor (which draws 90A) is running, the terminal voltage drops to 11.0 V. What is the internal resistance of the battery?
Homework Equations
V= EMF- Ir
The Attempt at a Solution
I think...
There are 2 types of temp rise measurement for electrical devices,
1)resistance type
2) thermocouple type (direct measurement)
My query is
1) which method is superior and please explain me the reason.
2) Which gives higher value of measurement?
Thanks in advance.
For the material used in a heater plate to generate heat for example, for a given amount of power (say 4.5 kw) does the higher resistance of the material mean it will produce a higher temperature? Or is it the other way around?
Homework Statement
I need to come up with an equation that would model the motion of a non-linear pendulum with air resistance. [/B]Homework Equations
Fc=mgsintheta
Fdrag=(1/2)p(v^2)CA
The Attempt at a Solution
I started with mgsintheta-(1/2)p(v^2)CA=ma
After substituting v=r*omega and...
I am comparing three brands of tires to see which one provides the lowest rolling resistance and thus give the best efficiency at low speeds. I have the information of the tires such as footprint, weight (of the tire and load), speed.
How would i go about doing this ? am really stumped
thanks
Homework Statement
A galvanometer of coil resistance 50.0 Ω deflects full scale for a current of 3.50 mA. What series resistance should be used with this galvanometer to construct a voltmeter which deflects full scale for 35.0 V
Homework Equations /Known Variables[/B]
R1 + R2... + Rn = Rtotal...
I am currently using a Wheatstone bridge to determine the resistance of a NTC thermistor(Futher information about thermistor: http://www.apogeeweb.net/article/38.html) and feed the difference to the setpoint (analog potentiometer) as the error signal to a PID controller, giving me a way to...
Homework Statement
What is the definition of resistance?
a. Resistance is the potential difference per unit current
b. Resistance is the gradient of the graph of potential difference against current
c. Resistance is the voltage required for a current of 1 A
d. Resistance is defined by the...
Homework Statement
What is the combined resistance when the switch is closed?
Homework Equations
IR=V
The Attempt at a Solution
I found that I1=5.2A and that I2=9.1A. The answers follow suit.
Now I thought that calculating the combined resistance with 60/(I1+I2) would be correct, however the...
Hello,
Given an infinitely long cylinder with a specified surface heat flux,
the thermal resistance of an annular region is given by,
R_th = ln(r_out / r_in) / (2 pi L k).
When I'm calculating the thermal resistance to the centerline, r_in = 0.
Does that mean there is infinite thermal...
Homework Statement
Prove the following equation:
## \Delta U=\frac {R_1R_4}{(R_1+R_4)^2}(\frac {\Delta R_1}{R_1}-\frac {\Delta R_2}{R_2}+\frac{\Delta R_3}{R_3}-\frac{\Delta R_4}{R_4})E##
This is used in Wheatstone bridge
Homework Equations
[/B]
U=RI
The Attempt at a Solution
This has...
Homework Statement
All resistors are ## R = 10 \Omega##
Homework Equations
Calculate the total Resistance
The Attempt at a Solution
all resistors are parallel, so
$$ \dfrac{1}{R_{AB}} = \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} $$
## R_{AB} =...
Homework Statement
There is a conductor with the square-shaped area. the Radii are r1 , r2 with width b and resistivity ## \rho_R##.
Find the resistance R between A and B
2. Homework Equations
##I = \iint_A\vec J \cdot d \vec A##
## \vec J = \kappa \vec E ##
## \vec E = \rho \vec J##
## V =...
Homework Statement
Homework Equations
parallel(two shared nodes in two sides), series resistor(one shared node between 2 resistors)
The Attempt at a Solution
I can't identify the circuit to be parallel or series in order to get the equivalent resistance.
how should I finish the question?
(...
Homework Statement
[/B]
What is the combined resistance in this circle between A and B.
Homework EquationsThe Attempt at a Solution
Honestly I have no idea what to here, any explanation will be great.
Homework Statement
[/B]
I'm going exercises and I understand that if the circuit is short circuited that R=10 ohm is 0. (Trying to find Thevelin R in all of these btw)
But then I ran across this one where when it's short circuited, isc is found using the current divider principle and it's...
Homework Statement
Find the Thévenin resistance for each of the circuits shown by zeroing the sources.
Homework EquationsThe Attempt at a Solution
I replaced the current source with an open circuit and I'm left with a wye formation but I don't know how to calculate the equivalent resistance
Homework Statement
Homework Equations
V = I.R
The Attempt at a Solution
6 ohm and 3 ohm are series = b
Then b pararel to 9ohm = c = total resistance
b = 9ohm
c = 9/2 ohm
I = V/R
I = 9.6/c
I = 2,13 A
Can you help me?
Is it right? My friend's answer is 0,8
Given two sets of load resistances and output voltages:
Rload = 108 ohms - Vout = 9.6V
Rload = 10 Ohms - Vout = 2.3V
Find the source voltage and the output voltage when R1 and R2 are equal.
When the resistance is very large, the voltage seems to be around 9.6. My assumption was that then the...
Hey everyone, I'm hoping that you guys will be able to help me with some calculations. I was on YouTube and came across this:
I then began to wonder if I could make a solenoid using bitter disk as in the video, granted no where near as powerful. I would say 1 tesla using an iron core. After...
Homework Statement
[/B]
It is required to find the current through the ammeter, marked A, in the above figure.Homework Equations
##V=iR##The Attempt at a Solution
I've redrawn the circuit as follows -
But don't know how to obtain the value ##i_3##
Not sure if this is more appropriate for physics or for differential equations, but this problem centers around an airplane traveling with air resistance. I am not looking to get the most realistic-possible model, as it is just for a video game I am making.
Although this is technically a PDE...
Given the circuit, I am supposed to find the total resistance, but I am unsure of what to do without having a voltage or current source with an internal resistor.
Homework Statement
[/B]
I am working on a lab report regarding the creation of an electromagnet using an iron core solenoid (just a nail wrapped with copper insulated wire). Before continuing with the creation of the electromagnet, I had to answer some questions regarding my knowledge of...
Question
Calculate resistance between terminals 1 and 2, 1 and 4, 1 and 3, 2 and 4, 3 and 4, and 2 and 3
My attempt of solution:
For R between 1 and 2 i done: (R1 + R2) || (R1 +R2 + R3)
The problem is:
Im not sure how to find which is in series and what's in parallel so I'm confused and I...
Homework Statement
1. For the first measurement, a load resistance Rload = 119Ohms results in an output voltage V(OUT) = 11Volts. For the second measurement, Rload = 11Ohms results in an output voltage V(OUT) = 3.2Volts. From these two measurements, determine the output voltage V(OUT) when...
Homework Statement
Homework Equations
at point C:
i2 - i3 - i4
i2 = i3 + i4[/B]
The Attempt at a Solution
I labeled all the currents going through each resistor in the picture[/B]
for loop ABC:
2000i1 = 3000i2 + 4000i3
for loop BDC:
3000i5 = 2000i4 + 4000i3
at point C:
i2 - i3 - i4
i2...
I've had a side project in mind for a while involving motorized Rollerblade wheels, however I need to figure out a motor size that would give me the needed torque to actually accelerate 250lbs up to 25mph. I realize even a 5hp electric motor is large but I was wondering if ohms have any affect...
Homework Statement
1. A sinusoidal source with RMS voltage V = 11Volts across a resistor R = 50Ohms, determine the dBm value. Hint: you will first have to determine the power delivered and then check the formula for dBm calculations.
2. A type of coaxial cable has a loss of 12dB/100m at some...
Homework Statement
https://imgur.com/a/aVCeU
Homework Equations
(1/Req) = (1/Rv1) +(1/Rv2)
Req = Rv1 + Rv2
The Attempt at a Solution
I'm not sure which formula is the correct one to use.So..
I'm absolutely stuck. I tried downloading a bunch of circuit board simulators, but I couldn't find an...
Homework Statement
The resistance of thermistor over a limit range of temperature is given by equation R=c/(T-203). Where c is constant ant T is absolute temperature. What would be temperature on centigrade scale of thermistor at absolute temperature T=300k?
Homework Equations
i)R=c/(T-203)...
Homework Statement
[/B]
Hi everyone! So I've got this similar problem as I posted yesterday, but this one
is slightly different due to the presence of gravity:
A particle in gravitational field ##~~g##
starts traveling upward (positive direction) along the y-axis from ##~~y=0##
with the...