DC circuits

Question 1

Magnetic field

Answer 1

A magnetic field is a region of space where a magnetic pole experiences a force.

Question 2

Magnetic flux density

Answer 2

The magnetic flux density at a point is defined as the force per unit current per unit length of a conductor when the conductor is placed at right angles to the field.

Question 3

Magnetic flux

Answer 3

The magnetic flux is the product of an area and the component of flux density perpendicular to that area

Question 4

Magnetic flux linkage

Answer 4

Magnetic flux linkage is defined as the product of the number of turns of the coil and the magnetic flux linking each turn

Question 5

Laws of EMI

Answer 5

1. Faraday’s law states that the induced emf in a circuit is directly proportional to fee rate of change of magnetic flux linkage
2. Lenz’s law stares that the direction of the induced emf is such that it produces effects to oppose the change causing it

Question 6

Root mean square value

Answer 6

Root mean square value of an ac is defined as the value of the steady direct current that would dissipate heat at the same rate as the ac in a given resistor