Electromagnetism

Question 1

What is electric field strength?

Answer 1

• the electric field strength, E, at a point is defined as the electric force exerted per unit positive charge acting on a small stationary charge placed at that point

Question 2

What is electric field?

Answer 2

• electric field is a region of space where a stationary charge experiences a force
• the direction of the electric field is the direction of the force on a positive charge

Question 3

What is a magnetic field

Answer 3

• it is a region of space in where a magnetic pole, a current-carrying conductor or a moving charge particle will experience a force

Question 4

What is magnetic flux density?

Answer 4

• is defined as the force acting per unit length on a straight wire which carries a unit current and is at right angles to the direction of the magnetic field
• SI unit: tesla(T)
• B = F/IL

Question 5

Effect of a ferrous core on the magnetic field

Answer 5

• magnetic flux density can be strengthened by the presence of a ferrous core due to alignment of magnetic domains with the external B-field