Question

After a capacitor is charged, it is removed from the power source. The separation between the plates is 3.0 mm and the electric field at a midpoint between the plates is 100 V/m. When the plates are pulled to a separation of 6.0 mm, the electric field at midpoint between the plates is:___________

Answer 1

50V/m

The electric field between the plates of a capacitor is directly proportional to the voltage and inversely proportional to the distance between the plates. This relationship is given by the formula E = V/d, where E is the electric field, V is the voltage, and d is the distance between the plates.

In the first scenario, the capacitor is charged and the separation between the plates is 3.0 mm. The electric field at the midpoint between the plates is 100 V/m. We can use the formula to find the voltage across the capacitor:

E = V/d

100 V/m = V/0.003 m

V = 0.3 V

Therefore, the voltage across the capacitor is 0.3 V.

In the second scenario, the plates are pulled apart to a separation of 6.0 mm. We can use the same formula to find the electric field at the midpoint between the plates:

E = V/d

E = (0.3 V)/(0.006 m)

E = 50 V/m

Therefore, the electric field at the midpoint between the plates is 50 V/m. This is half of the original electric field, since the distance between the plates has doubled.