Understanding Magnetic Fields in Coils

What is the direction of the magnetic field inside a coil of wire with current flowing through it?

• From bottom to top

• From top to bottom

• From right to left

• From left to right

What tool can be used to visualize the magnetic field lines inside a coil?

• A barometer

• A thermometer

• A voltmeter

• Iron filings

How do compass needles behave when a current is passed through a coil?

• They point parallel to the coil's length

• They point perpendicular to the coil's length

• They do not move

• They spin randomly

Which of the following factors is directly proportional to the magnetic field strength in a coil?

• The temperature of the coil

• The number of turns in the coil

• The length of the coil

• The color of the coil

What happens to the magnetic field strength if the length of the coil is increased?

• It increases

• It decreases

• It remains the same

• It doubles

What is the role of relative permeability in a coil's magnetic field?

• It decreases the magnetic field strength

• It has no effect on the magnetic field

• It increases the magnetic field strength

• It changes the direction of the magnetic field

What is the relative permeability of air?

• 0

• 1

• 100

• 200

How does inserting an iron core into a coil affect its magnetic field strength?

• It reverses the field direction

• It decreases the field strength by a factor of 200

• It has no effect on the field strength

• It increases the field strength by a factor of 200

In the example calculation, what is the magnetic field strength of the coil with an air core?

• 6 Tesla

• 3 milliTesla

• 200 Tesla

• 1.2 Tesla

What is the magnetic field strength of the coil when an iron core is used?

• 1.2 Tesla

• 3 milliTesla

• 200 Tesla

• 6 Tesla