Electric field in a platinum wire

AI Thread Summary
To calculate the electric field in a platinum wire carrying 0.3 amperes of current, the relevant equations involve conductivity and the relationship between current, charge density, and electric field. The initial calculation yielded an incorrect value of 3e-5 due to unit conversion issues. By adjusting the units correctly, the accurate electric field strength was determined to be 0.03. The discussion highlights the importance of careful unit management in physics calculations. Ultimately, the correct application of formulas leads to the right answer.
sdevoe
Messages
21
Reaction score
0

Homework Statement



Consider a platinum wire (σ = 1.0e+7) with a cross-sectional area of 1 mm^2 (similar to your connecting wires) and carrying 0.3 amperes of current, which is about what you get in a circuit with a round bulb and two batteries in series. Calculate the strength of the very small electric field required to drive this current through the wire.

Homework Equations



σ=qnu
I=qnAuE
Therefore I=σAE
where phi is the conductivity A the cross sectional area and E the electric field

The Attempt at a Solution


This seemed easy but i got an answer of 3e-5 and that is incorrect?
 
Physics news on Phys.org
Never mind i figured it out
 
How did you do it? I am where you were in the first post.
 
Hey I figured it out.
The only problem was dealing with units.
I just multiplied the 3e-5 by 1000 and got .03 as the right answer.
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged 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...
View full post »

Similar threads

Change in the Electric Field Due to a Copper Wire Being Inserted
Replies
14
Views
5K
Platinum resistance thermometer and Kirchoff's Laws
Replies
1
Views
3K
What causes electric field/ magnetic field?
Replies
3
Views
2K
Finding magnetic field using Ampere's Circuital Law
Replies
5
Views
924
Length of Wire Effect on Current and Inner Electric Field.
Replies
4
Views
4K
Induced Electric Field In Circuit With Varying Resistance
Replies
3
Views
2K
Magnetism: magnetic feild strength of a wire
Replies
3
Views
2K
What is the optimal thickness of a coating to reduce a wire's resistance by 50%?
Replies
6
Views
3K
Infinite Wire/Surface charge question
Replies
2
Views
1K
Electric currents and Magnetic fields
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top