Magnetism

Question 1

Magnet

Answer 1

Body with magnetic property

Question 2

Electromagnet

Answer 2

Shows magnetic properties as long as there is electric current passing through them

Question 3

Magnetic moment

Answer 3

Strength of the magnet

Question 4

Magnetic field

Answer 4

Magnets create a magnetic field around themselves and exert forces by this field on one another even over relatively long distances. Structure, strength, and direction is visualized by field lines

Question 5

Density of field lines indicates

Answer 5

Strength of the field

Question 6

Structure of magnetic field lines

Answer 6

Magnetic field lines are closed loops that end at the same pole they originated from

Question 7

Magnetic flux density

Answer 7

Strength of a magnetic field and the forces acting on a magnet in an external magnetic field.

Question 8

Si unit of magnetic flux density (B)

Answer 8

Tesla

Question 9

The magnetic effect of electric current

Answer 9

A conductor generates a magnetic field around itself if electric current flows through it. The magnetic flux density is proportional to the electric current. The field becomes more concentrated if the conductor is wound up in a coil. Fields created by individual turns are added up creating a combined field with a flux density proportional to the number of turns. The field inside the coil is strong and homogenous.

Question 10

Advantages of electromagnets

Answer 10

Strong and homogenous field. Strength can be controlled by the current and it can be switched off.

Question 11

Electromagnetic induction

Answer 11

A magnetic field that changes over time generates an electric field.

Question 12

Induced voltage

Answer 12

When a permanent magnet is moved inside a coil and electricity is induced

Question 13

Lenz’s law

Answer 13

The induced voltage and current will act against the phenomenon creating it