Final answer:
The electric field between two oppositely charged plates connected to a 100V battery and separated by 10 cm is 1000 V/m.
Step-by-step explanation:
The magnitude of the electric field between two oppositely charged plates connected by a 100V battery and separated by a distance of 10 cm can be calculated using the formula for the electric field (E) created by a uniform electric field between two parallel plates, which is E = V/d. Here, V represents the voltage between the plates, and d is the separation distance between them. In this case, V is 100 volts and d is 10 cm, which needs to be converted to meters (0.10 m).
The magnitude of the electric field is therefore E = 100 V / 0.10 m = 1000 V/m.