PHYS-153 Final Exam Definitions and Concepts

Take a look at the equation for the e/m ratio: e/m = 2V/B^²r^²

If V is along the Y-axis, the quantity on the X-axis should be ______. This will yield a slope equal to e/m.

B²r²/2

When the velocity vector is perpendicular to the magnetic field vector (B), the electrons move in a ________________________ in the plane perpendicular to B.

uniform circular motion

When the velocity vector is at some arbitrary angle:

• Creates a straight-line motion, as the magnetic force is zero.

• Causes circular motion, resulting in a helical path (through helical motion) with the axis along the magnetic field lines.

Electromagnetic Induction

The generation of electricity using magnetic field.

Magnetic Flux

The number of magnetic field lines passing through an area (loop of wire/coil).

Faraday’s Law of Electromagnetic Induction

A voltage (EMF) is induced in a circuit when there is a changing magnetic flux passing through the circuit.

Equation: E = -d(flux)/d(time)

The more rapidly the magnetic flux changes, ____________________________.

the stronger the EMF generated

Lenz’s Law

Gives the direction of the induced EMF and current.