[Physics Class Notes] on Magnetic Effects of Electric Current Pdf for Exam

There are three effects of electric current. They are magnetic effect, heating effect, and chemical effect. When an electric current flows through a wire a magnetic field is generated around the wire and this can be determined by the deflection of a compass. The magnetic field has a direction along with a magnitude. If the electric current flows in a direction north to south the direction in which the magnetic compass will deflect is clockwise implying that the direction of the magnetic field is dependent on the direction of flow of the electric current. Conventionally it is taken that magnetic lines emerge from the north pole and merge at the south pole. Magnetic field lines from two magnets cannot cross each other. The magnitude of the magnetic field increases with the increase of electric current through the wire. The SI unit of the magnetic field is Tesla.

Electricity and magnetism are bound to each other, and it is proven that it produces a magnetic effect when the electric current passes through the copper wire.

Magnetic Field

The magnetic field is a quantity that has magnitude as well as direction.

A magnetic field’s direction is usually taken as the direction in which a compass needle’s north pole travels inside it.

The convention is for the field lines to emerge from the north pole and merge at the south pole.

No two-magnet bar field lines are found to cross one another. If this occurs, it implies that the compass needle will point to two directions at the point of intersection, which is not feasible.

With the increase of current through the wire, the magnitude of the magnetic field produced by an electric current at a given point increases.

Right-Hand Thumb Rule

The right-hand thumb rule, also known as Maxwell’s corkscrew law, describes the direction of the magnetic field associated with a current-carrying conductor.

Right – hand thumb rule states that “Imagine holding current with a straight conductor in your right hand, so the thumb points in the current direction. Then curl your conductive fingers towards the magnetic field lines.

Fleming’s Left-Hand Rule

Fleming’s left-hand rule says, “Stretch the left thumb, forefinger and middle finger to be perpendicular to each other. If the first finger points in the direction of the magnetic field and the second finger in the direction of the current, the thumb points in the direction of motion or the driver’s force.”

The human body also produces a magnetic field, but it is minimal and about one-billionth of the magnetic field on earth.

The heart and brain are the two main organs in the human body that created the magnetic field.

The magnetic field within the human body forms the basis for obtaining images of various parts of the body.

The technique used to get the body part image is known as MRI Magnetic Resonance Imaging.

Electric Motor

An electric motor is a rotating system designed to transform electric power into mechanical power.
We have hundreds of appliances that use electric motors, such as fridges, mixers, fans, washing machines, computers, etc.

(Image to be added soon)

1. An electromagnet instead of a permanent magnet.

2. A Large number of conductive wires turns in the coil bearing electrical current.

The soft iron core wound is known as an armature, with the coil wound and the coils wounded.
The armature has the main function to maximize engine power.

Fleming’s Right-Hand Rule

If the forefinger indicates the magnetic field direction and the thumb indicates the conductor’s motion direction, then the middle finger indicates the direction of the induced current.

Electric Generator