Between two large parallel plates with a potential difference V and separation d, the field is
Electric Fields - OCR A-Level Physics
- Between two large parallel plates with a potential differenceThe energyThe capacity to do work. Measured in joules (J). transferred per unit chargeA property of matter that causes it to experience a force in an electromagnetic field. Measured in coulombs (C). between two points. Measured in volts (V). V and separation d, the field is approximately uniform (constant magnitude and direction everywhere between the plates).
- Field lines are parallel, equally spaced, and perpendicular to the plates.
- Edge effects cause the field to become non-uniform near the edges of the plates - this is usually ignored in calculations.
$$E = \frac{V}{d}$$
Examiner Tips and Tricks
- A charged particle between parallel plates follows a parabolic path (like projectileAn object moving freely under gravity after being launched. Horizontal and vertical components of motion are independent. motion).
- Use $E = V/d$ for the field, then $F = EQ$ for the force, then $a = F/m$ for the accelerationThe rate of change of velocityThe rate of change of displacement. A vector quantity. Measured in m s⁻¹.. A vector quantity. Measured in m s⁻². - this is constant and perpendicular to the initial velocityThe rate of change of displacement. A vector quantity. Measured in m s⁻¹..