DC Transmission Line II (3 of 4)
Force due to potential – dielectric energy
Force due to potential – dielectric energy
Dielectric Energy – from page 17, Table I
The energy w in joules from capacitance C in farads and potential e in volts
My belief is that the force is the derivative of w with respect to s (in cm) However, to be consistent with e remaining constant while C changes, the source of e in the circuit must do work. So once again I wing it:
Find C in terms of s. Use the capacitance of circuit from above
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_farads_parallel_wires.png)
Now take the derivative with respect to s
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_farads_per_cm_s.png)
Substituting into the Force equation from above:
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_force_calc_j_per_cm.png)
Convert Newton-meters (joules) per cm to Newtons and then Newtons to ounces
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_force_calc_3_ounces.png)
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_energy.png)
The energy w in joules from capacitance C in farads and potential e in volts
My belief is that the force is the derivative of w with respect to s (in cm) However, to be consistent with e remaining constant while C changes, the source of e in the circuit must do work. So once again I wing it:
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_energy_per_cm.png)
Find C in terms of s. Use the capacitance of circuit from above
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_farads_parallel_wires.png)
Now take the derivative with respect to s
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_farads_per_cm_s.png)
Substituting into the Force equation from above:
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_force_calc_j_per_cm.png)
Convert Newton-meters (joules) per cm to Newtons and then Newtons to ounces
![](http://i1123.photobucket.com/albums/l552/z377/E_F/EF_PWHWEPD_601/C_force_calc_3_ounces.png)
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