Electromagnetic Induction

The total number of magnetic field lines passing through an area is termed as?

• Voltage

• EMF

• Magnetic flux

• Magnetic flux density

Magnetic flux involves __________ and _________.

• magnetic field and surface area

• induction and surface area

• magnetic field and induction

• electromagnetic induction and surface area

______ Law says that the Induced current is proportional to the change of magnetic flux

• Lenz's

• Faraday's

• Ampere's

Faraday's law states that𝜺=−𝑵 𝒅𝝓/𝒅𝒕 , what is the physical meaning of the equation?

• The magnetic field direction is propotional to the current of loop

• The induced emf is proportional to the rate change of magnetic flux

• The current of circuit proportional to voltage applied in the circuit

• The induced emf is not equal to change of magnetic field

"An induced current always flow in a direction that opposes the change in magnetic flux that causes it". this is the statement for?

• Fleming’s left hand rule

• Fleming’s right hand rule

• Faraday’s law

• Lenz’s law

How can the magnetic flux through a coil of wire be increased? Select two answers:

• Increase the magnitude of the magnetic field that passes outside the loop

• Increase the magnitude of the magnetic field that passes through the loop.

• Increase the cross sectional area of the loop.

• Orient the loop so its normal vector is perpendicular to the external magnetic field direction.

Changing current in a coil produces emf in the same coil. this phenomenon is known as

• Mutual induction

• Self induction

• induced emf

• induced current

Self induced emf is always proportional to the time rate of change of the current.

• True

• False

SI unit for self inductance, L is

• Tesla(T)

• Weber(Wb)

• Henry(H)

• Farad (F)

When a constant current of 5.0 A flows in a 400 turns solenoid of length, l and cross sectional area A, emf is induced in the coil.

• True

• False