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- Homework Statement
- Two parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. What is the magnitude of the electric field strength between them, if the potential 7.85 cm from the zero volt plate (and 2.15 cm from the other) is 693 V?

- Homework Equations
- E = V/D

I'm really unsure about how to solve this because I am not given the total voltage between the plates. The voltage given (693V) is at a point that is 7.85 cm away from the zero volt plate. If I was given the total voltage between the complete distance between the plates (10 cm), then I could just use E=V/D and solve. But this is not the case. My initial thought was to just say that the total distance between the plates is 7.85 cm, not 10cm. Then, I can solve for the E-field using the voltage given and the distance of 7.85 cm:

E = 693/.0785m = 8828.025

Then, I could find the voltage between the plates at 10cm separation using this value as my E-field, then use this voltage to solve for my E-field:

V = E*(.1m) = 8828.025*(.1m)

However, this makes no sense because the E field that I calculated was for a voltage of 693 and distance of 7.85cm between the plates. If E=V/D, then the E field will change in magnitude as the distance between the plates changes. So I cant just plug in this value of E in order to find the voltage between the plates at 10cm apart. My brain is just hurting now. Please help.

E = 693/.0785m = 8828.025

Then, I could find the voltage between the plates at 10cm separation using this value as my E-field, then use this voltage to solve for my E-field:

V = E*(.1m) = 8828.025*(.1m)

However, this makes no sense because the E field that I calculated was for a voltage of 693 and distance of 7.85cm between the plates. If E=V/D, then the E field will change in magnitude as the distance between the plates changes. So I cant just plug in this value of E in order to find the voltage between the plates at 10cm apart. My brain is just hurting now. Please help.