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posted by  Mr.hero on 11/5/2009 2:24:11 AM  |  status: Closed  |  Earned Karma: 135

answer the oneyou know and will rate you lifesaver!!!

Course Textbook Chapter Problem Needs by
Calculus Based Physics Essential University Physics Volume 1 (1st) by Wolfson 29 64 11/12/2009 at 11:00:00 PM
Question Details:
Answer Any two and I will rate you lifesaver!!!

A cylindrical resistor of length L, radius a, and resistance R carries a current I.
Part A
Calculate the electric field at the surface of the resistor, assuming the electric field is uniform throughout, including at the surface.
Express your answer in terms of some or all of the variables L, a, R, I, and constant mu_0.

Part B
Calculate the magnetic field at the surface of the resistor.
Express your answer in terms of some or all of the variables L, a, R, I, and constant mu_0.


Part C
Calculate the magnitude of the Poynting vector.
Express your answer in terms of some or all of the variables L, a, R, I, and constant mu_0.


Part D
What is the direction of the Poynting vector?
into the resistor
out of the resistor
along the resistor


Part E
Calculate the flux of the Poynting vector (that is, \int {\vec S} \, \cdot \,d\vec A) over the surface of the resistor to get the rate of electromagnetic energy flow into the resistor.
Express your answer in terms of some or all of the variables L, a, R, I, and constant mu_0.
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AAnswers:

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Oracle
Karma Points: 11,849
posted by Physics-Ga on 11/5/2009 2:51:41 PM  |  status: Live
Asker's Rating: Lifesaver   
Response Details:
A) W = E q L = V q
E = V / L = I R / L
B) 2 π a B  = μ0 I 
B = μ0 I / (2 π a)
C)   S = (1 / μ0)   E X B  = E * B / μ0    since the fields are right angles
D)  The Poynting vector is directed into the resistor perpendicular to the current
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