magnetism and electromagnetism

Question 1

what is magnetic field line?

Answer 1

a line shows the direction of a magnetic field

Question 2

what is a uniform magnetic field?

Answer 2

the magnetic field lines are parallel and same directions

Question 3

is the direction of the magnetic field the same as the direction of the current?

Answer 3

no use the right hand grip rule to find the field.

Question 4

how can you tell which way the forces act?

Answer 4

by Fleming’s left hand rule

Question 5

the larger the electric current, the x the magnetic field is

Answer 5

stronger

Question 6

how to speed up the electric motor?

Answer 6

more current
more turns on the coil
stronger magnetic field
a soft iron core in the coil

Question 7

is the direction of magnetic field from south to north?

Answer 7

no from north to south

Question 8

how to produce a magnetic field?

Answer 8

an electric current in a conductor produce magnetic field

Question 9

how can a loudspeaker produce sound wave?

Answer 9

change the current constantly and produce vibration

Question 10

what is the opposite word of attraction?

Answer 10

repulsion