Learners observe the motion of a charged particle in a uniform magnetic field. By varying the voltage and the distance between plates, learners change the electric field between the plates and observe how the charged particles motion is affected by the resulting electric field.
After completing this tutorial, you will be able to complete the following:
Coulomb's law calculates the electric force resulting from charged particles as F = (k.q1..q2)/r2. The combined forces resulting from one or more charges is the electric field, defined as the electric force per unit of charge and shown by E = F/q. The vector quantity E is measured in newtons per coulomb (N/C) or volts per meter (V/M). This quantity is defined as the force that would be experienced by a test charge of 1 C at a given distance away from the field.
The electric field is represented by lines pointing toward negative charges and away from positive charges. Much like the gravitational field from a mass, the electric field on an isolated point charge spreads radially outward uniformly in all directions. But unlike gravity, which attracts all masses, an electric field exerts opposite effects depending on the test charge. On a positive charge, the electric field exerts a force in the direction of the field. A negative charge experiences a force in the opposite direction.
A uniform or constant electric field can be created by inducing a potential difference between two flat, parallel plates made of material with high electrical conductivity. This ensures even distribution of electrons. The potential difference between the plates and the distance between them determine the strength of the resulting electric field. Charged particles or electrons are then propelled between the plates and through the field, their path adjusted by electrodes. The strength of the field, the charge on the test particle, and the effects of the electrodes just before the particle enters the field all influence the trajectory of the particle. Many technologies, including the famous cathode ray tube, operate on this principle.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Define electric forcePerform calculations using Coulombs LawExplain an electric fieldDefine the potential difference|
|Type of Tutorial||Concept Development|
|Key Vocabulary||anodes, cathode ray tubes, cathodes|