مراجعة - فيزيا

When the wire is held stationary or moved parallel to the field

• nothing happens

• there is a current.

• reverses direction

• none

When the wire is moved perpendicular to the field

• nothing happens

• there is a current.

• reverses direction

• none

Which factor does not affect the induced emf?

• The angle between velocity and magnetic field

• The speed of the wire

• The magnetic field strength

• The resistance of the wire

Determine direction of induced current

• UP

• DOWEN

• INTO

• OUT

An induced electromotive force (EMF) is generated, causing the electric current to flow. As the armature turns, current varies between some maximum value and zero. The following conditions must be met (MORE THEN 1)

• The coil must cut the magnetic field lines.

• The coil must rotate inside the magnetic field

• Axis of rotations should not be parallel with magnetic field lines.

• Axis of rotations should be parallel with magnetic field lines.

When is the current zero?

• None

• the motion of the coil is perpendicular to the direction of the magnetic field.

• When the coil is in a vertical position.

• When the coil is in a horizontal position

which one is correct? (more then 1 ans..)

• AC : It is defined as an electric current whose direction and magnitude changes periodically

• AC : current that flows only in one direction

• ex;battry

• ex;generetor

Lenz’s law is used to find the direction of which of the following?

• flow of power

• Electromagnetic force

• Induced magnetic field

• Potential difference

1.What is the type of magnetic pole at end B?

• soth pole

• north pole

• poth

• sourth-north

• Faraday law

• orested law

• ohms law

• kirchof law