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Resistance between spherical conductors

Hi! I have a problem and I have no clue how to do it...

The space between two concentric spherical-shell conductors is filled
with a material that has a resistivity of 10^9 ohm meter. If the
inner shell has a radius of 1.5 cm and the outer shell has a radius of
5 cm, what is the resistance between the conductors?

I found a hint that says to find the resistance of a spherical shell
element of the material of area 4(pi)r^2 and length dr, and integrate
to find the total resistance of the set of shells in series.

Any help would be great! thanks
 
L

Lionel

Jan 1, 1970
0
Hi! I have a problem and I have no clue how to do it...

The space between two concentric spherical-shell conductors is filled
with a material that has a resistivity of 10^9 ohm meter. If the
inner shell has a radius of 1.5 cm and the outer shell has a radius of
5 cm, what is the resistance between the conductors?

I found a hint that says to find the resistance of a spherical shell
element of the material of area 4(pi)r^2 and length dr, and integrate
to find the total resistance of the set of shells in series.

Any help would be great! thanks

You really shouldn't be asking homework questions on Usenet. Have you
tried asking your official instructor?
 
P

Phil Allison

Jan 1, 1970
0
Hi! I have a problem and I have no clue how to do it...


** Try " alt.math ".

Yours is a math problem, not basic electronics.



........ Phil
 
H

Homer J Simpson

Jan 1, 1970
0
Hi! I have a problem and I have no clue how to do it...

The space between two concentric spherical-shell conductors is filled
with a material that has a resistivity of 10^9 ohm meter. If the
inner shell has a radius of 1.5 cm and the outer shell has a radius of
5 cm, what is the resistance between the conductors?

I found a hint that says to find the resistance of a spherical shell
element of the material of area 4(pi)r^2 and length dr, and integrate
to find the total resistance of the set of shells in series.

You don't know how to integrate such a function?
 
D

Dan Coby

Jan 1, 1970
0
John Larkin said:
That's correct. Treat each shell as a flat sheet of area equal to the
surface of the shell. That's a good approximation for a thin shell.

Please let him do his own homework. Otherwise he will not learn.
 
J

John Larkin

Jan 1, 1970
0
Hi! I have a problem and I have no clue how to do it...

The space between two concentric spherical-shell conductors is filled
with a material that has a resistivity of 10^9 ohm meter. If the
inner shell has a radius of 1.5 cm and the outer shell has a radius of
5 cm, what is the resistance between the conductors?

I found a hint that says to find the resistance of a spherical shell
element of the material of area 4(pi)r^2 and length dr, and integrate
to find the total resistance of the set of shells in series.

That's correct. Treat each shell as a flat sheet of area equal to the
surface of the shell. That's a good approximation for a thin shell.

John
 
J

John Larkin

Jan 1, 1970
0
Please let him do his own homework. Otherwise he will not learn.

I didn't do the integration for him. A little visualization sometimes
helps, and I pretty much rephrased what he already knew.

John
 
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