Electrodynamics

Question 1

Magnetic flux density

Answer 1

Is a representation of the magnitude and direction of the magnetic field.


Question 2

Magnetic flux linkage

Answer 2

Product of the number of turns on the coil and the flux through the coil.


Question 3

Faraday’s law of electromagnetic induction

Answer 3

The emf induced is directly proportional to the rate of change of magnetic flux (flux linkage)


Question 4

Lenz’s law

Answer 4

The induced current flows in a direction so as to set up a magnetic field to oppose the change in magnetic flux


Question 5

Diode

Answer 5

A component that only allows current to flow in one direction


Question 6

AC: Alternating current

Answer 6

Current which reverses direction periodically.

Question 7

Commutator:​

Answer 7

A device which ensures that the direction of the current in a coil is reversed every half revolution.

Question 8

Conventional current

Answer 8

The rate of flow of positive charge from the positive terminal of the cell to the negative terminal.

Question 9

DC: Direct current

Answer 9

Current flowing in one direction only

Question 10

Electromagnetic induction

Answer 10

Occurs when a current is induced in a closed conducting loop when there is a change in the magnetic flux passing through the surface area of the conducting loop.

Question 11

Magnetic flux

Answer 11

For a loop of area (A) in the presence of a uniform magnetic flux density (B), the magnetic flux (Ф) passing through the loop is defined as Ф = BA cosθ, where θ is the
angle between the magnetic flux density (B) and the normal to the loop of the area (A).