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:
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top