What Happens to Circuit Current When Temperature Drops Below Tc?

Click For Summary

Homework Help Overview

The discussion revolves around a circuit containing a type-I superconductor with a transition temperature Tc. The original poster seeks to understand the behavior of current in the circuit as the temperature drops below Tc, specifically regarding the roles of the resistor and capacitor in this scenario.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the implications of superconductivity on circuit behavior, questioning how the capacitor behaves when the resistance drops to zero. There are attempts to clarify the relationship between voltage across components and the flow of current in the circuit.

Discussion Status

Some participants are actively engaging with the problem, raising questions about the nature of type-I superconductors and the behavior of capacitors in this context. There is a recognition of the need for further clarification and equations to describe the persistent current, but no consensus has been reached on the specifics.

Contextual Notes

Participants express uncertainty about the properties of type-I superconductors and the implications of the Meissner effect. There is also a mention of the need for equations to support the discussion, indicating a desire for a deeper understanding of the underlying physics.

Reshma
Messages
749
Reaction score
6
In the given circuit, Resistance R is made up of type-I superconducting material with transition temperature Tc. The initial temperature of the circuit is T(>Tc). At time t=t0 the temperature is dropped below Tc. Find the current in the circuit at:
1] at t<t0 and through AB
2] at t=t0
3] at t>t0

My answer:

When the temperature is above the critical temperature, the circuit behaves normally. When the temperature is dropped below the crictical temperature, the resistance becomes R=0 and you get a persistent current. My problem is, I don't know what happens to the capacitor in the circuit once the temperature falls below Tc. Explanation needed...
 

Attachments

Physics news on Phys.org
Come on guys, help me out here! I don't think it is that difficult.
 
The voltage on both the resistor and the capacitor should be equal to the battery's voltage at all times. I don't know what's a type I superconductor, but I assume it's resistance drops to 0 once it's temperature drops below Tc. Therefore, capacitor will always remain fully charged and no current will flow through it, but infinite current will flow through the rest of the circuit.
 
pseudovector said:
The voltage on both the resistor and the capacitor should be equal to the battery's voltage at all times. I don't know what's a type I superconductor, but I assume it's resistance drops to 0 once it's temperature drops below Tc. Therefore, capacitor will always remain fully charged and no current will flow through it, but infinite current will flow through the rest of the circuit.
Thanks for replying!
Type I superconductors exhibit complete Meissner effect. I need to set up an equation to show that there is a persistent current in this circuit once the temperature falls below Tc. Any clues on how to proceed?
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 37 ·
2
Replies
37
Views
10K
  • · Replies 6 ·
Replies
6
Views
4K