Resistor and power output varying with a distance x

AI Thread Summary
The discussion revolves around calculating the power dissipated in a resistor as a function of the distance x, with a battery connected across a uniform resistor. Participants express confusion about how to approach the problem, particularly regarding the arrangement of resistors and how to calculate total resistance as x varies. The equations for power and resistance in parallel are referenced, but clarity on the specific configuration is lacking. There is a request for further explanation and assistance in visualizing the circuit setup. The conversation highlights the need for a better understanding of resistor configurations and their impact on power dissipation.
Jonnyto
Messages
12
Reaction score
0

Homework Statement


Figure 29 shows a battery connected across a uniform resistor R0. A sliding contact can move across the resistor from x=0 at the left to x=10 cm at the right. Find an expression for the power dissipated in the resistor R as a function of x. Plot the function for ℰ=50 V, R=2000Ω , and R0=100Ω


Homework Equations


P=\frac{V<sup>2</sup>}{R}



The Attempt at a Solution


I have no clue at all on how to solve this problem. I think that it might have to do with how resistors are adding up in parallel. I really can't see which one is in parallel. I don't see how to determine the resistance with the varying x.

fig29.JPG
 
Physics news on Phys.org
This circuit is equivalent to three resistors: Rl, Rr, and R. Rl and Rr are the left and right, correspondingly, parts of Ro; their values depend on x. Solve for voltage at R and current through it.
 
It's helpful to post a full size image if it's not too large.

attachment.php?attachmentid=58418&d=1367488623.jpg
 
may be this be help..
R_{total}=(R // R_{p}) + R_{s})
upload1.JPG


just as Voko said #2
 
Complex

arifz2303 said:
may be this be help..
r_{total}=(r // r_{p}) + r_{s})




just as voko said #2

please explain more about the problem
 
Last edited by a moderator:
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top