Calculating the Average Current of a Rotating Charge q | Insulating String

  • Thread starter Thread starter eagleswings
  • Start date Start date
  • Tags Tags
    Weird
Click For Summary
The discussion revolves around calculating the average current of a rotating charge q on an insulating string. The key point is that while the charge does not change (dq/dt = 0), it still represents a current due to its circular motion. The average current can be derived from the relationship I = q/T, where T is the period of rotation. The equation I = qw/2π is suggested as a way to express the current in terms of angular frequency. The conversation highlights the confusion around the concept of current in this context, ultimately leading to a clearer understanding of the average current for a rotating charge.
eagleswings
Messages
15
Reaction score
1
[SOLVED] really weird one

Homework Statement

A small sphere that carries a charge q is whirled in a circle at the end of an insulating string. the angular frequencyy of rotation is omega [w]. What average current does this rotating charge represent?



Homework Equations

I = dQ/dt; w = 2(pi)/T; x[t] = Acos[wt +C];



The Attempt at a Solution

; this question doesn't make sense to me. q never changes - it just travels in a circle - so dq/dt =0;there is one charge going in a circle, but not axially which would represent charge in a conduit. is this a picture of alternating current? [we haven't gotten to that yet].
 
  • Like
Likes Shan promiz
Physics news on Phys.org
Current is the net charge per unit time passing a given point. On any point on the circumference, what is that value?
 
That would be qw = charge per second. surely not that simple. thanks
 
Should be q/T = qw/2pi.
 
thanks shooting star!
 

Thread 'Magnitude of buoyant force in fluids of different densities'

The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?
View full post »

Similar threads

Discharging a capacitor -- Calculate the current as a function of time
  • · Replies 3 ·
Replies
3
Views
2K
Average battery current in battery charger
  • · Replies 7 ·
Replies
7
Views
1K
Finding the average energy in an RLC circuit
  • · Replies 9 ·
Replies
9
Views
2K
Find the charge q(t) for an LC circuit
  • · Replies 2 ·
Replies
2
Views
3K
Whats the average current does this rotating charge represent
  • · Replies 5 ·
Replies
5
Views
4K
Charge passing through a cross section for a time varying current
  • · Replies 2 ·
Replies
2
Views
4K
Calculating Heat Generated in a Coil due to Changing Current and Resistance
  • · Replies 22 ·
Replies
22
Views
6K
Foucault Pendulum at the North Pole
  • · Replies 9 ·
Replies
9
Views
2K
Energy dissipated by resistor problem
  • · Replies 3 ·
Replies
3
Views
3K
How Do You Calculate Current from a Single Oscillating Charge?
  • · Replies 10 ·
Replies
10
Views
3K