PRASHANT KIRAD
Magnetic Effect of Electric Current Hans Christian Oersted (1820):
Discovered that electric current deflects
Magnet: is any substance that attracts iron or iron like
a compass needle, proving the link
substances.
between electricity and magnetism.
Properties of Bar Magnet:
A freely suspended bar magnet aligns in the Earth's north- Hans
south direction. Christian
Attractive and Repulsive Forces: Like poles repel, opposite Oersted
poles attract.
Dipole Nature: Always has two poles (north and south);
cutting the magnet creates smaller magnets, each with two Maxwell's Right Hand Thumb Rule
poles. The rule states that if a straight conductor
Creates a magnetic field around it where its effect can be carrying current is held in the right hand such
felt. that the thumb is pointed in the direction of the
It retains its magnetic properties over time. current, then the direction in which your fingers
Magnetic Field: is the area around a magnet in which the encircle the wire gives the direction of the
effect of magnetism is felt. magnetic lines of force around the wire
Magnetic field lines are imaginary lines that show the Thumb = upwards, curled fingers = magnetic field (clockwise),
strength and direction of a magnetic field. the field direction = anticlockwise.
Properties of Magnetic Filed Lines: Thumb = downwards, curled fingers = magnetic field
Magnetic field lines start at the north pole and end at (anticlockwise), the field direction = clockwise
the south pole.
Closer lines mean a stronger magnetic field (near
Magnetic field lines due to
poles).
Straight conductor
Field lines never cross each other.
They form closed continuous curves.
Magnetic field lines due to current carrying loop
They show the direction of magnetic force.
circular pattern
around the arms
straight at the
center of the loop
Horseshoe Bar magnet
shaped
Magnetic field lines due to Solenoid Fleming’s Left Hand Rule
electromagnet.
A coil of many circular turns of When a current-carrying conductor is placed in
insulated copper wire wrapped an external magnetic field, the conductor
closely in the shape of a cylinder. experiences a force which is mutually
Outside the solenoid: North to perpendicular to both the Magnetic field and to
South the direction of the current flow.
Inside the solenoid: South to North Stretch the thumb, forefinger, and middle finger
Factors: number of turns in the coil, of your left hand perpendicular to each other.
amount of current flowing through
it, radius of coil, Material of core of Forefinger = Magnetic field
the solenoid. direction, Middle finger =
Current direction, Thumb =
Force/motion direction.
Force on a current carrying conductor
in a magnetic field Domestic Circuit
1/100 second in India, i.e. the Potential Difference in
frequency of A.C in India is 50 Hz. India: 220V at 50Hz.
Alternating Current (AC) Direct Current (DC)
AC can travel safely over long DC cannot travel long distances;
distances, even between cities. it loses power.
Frequency is 50 or 60 Hz,
DC has zero frequency.
depending on the country.
Current direction reverses Current flows steadily in one
periodically. direction.
Cheaper then DC generation Expensive then AC generation
Magnetic Effect of Electric Current Hans Christian Oersted (1820):
Discovered that electric current deflects
Magnet: is any substance that attracts iron or iron like
a compass needle, proving the link
substances.
between electricity and magnetism.
Properties of Bar Magnet:
A freely suspended bar magnet aligns in the Earth's north- Hans
south direction. Christian
Attractive and Repulsive Forces: Like poles repel, opposite Oersted
poles attract.
Dipole Nature: Always has two poles (north and south);
cutting the magnet creates smaller magnets, each with two Maxwell's Right Hand Thumb Rule
poles. The rule states that if a straight conductor
Creates a magnetic field around it where its effect can be carrying current is held in the right hand such
felt. that the thumb is pointed in the direction of the
It retains its magnetic properties over time. current, then the direction in which your fingers
Magnetic Field: is the area around a magnet in which the encircle the wire gives the direction of the
effect of magnetism is felt. magnetic lines of force around the wire
Magnetic field lines are imaginary lines that show the Thumb = upwards, curled fingers = magnetic field (clockwise),
strength and direction of a magnetic field. the field direction = anticlockwise.
Properties of Magnetic Filed Lines: Thumb = downwards, curled fingers = magnetic field
Magnetic field lines start at the north pole and end at (anticlockwise), the field direction = clockwise
the south pole.
Closer lines mean a stronger magnetic field (near
Magnetic field lines due to
poles).
Straight conductor
Field lines never cross each other.
They form closed continuous curves.
Magnetic field lines due to current carrying loop
They show the direction of magnetic force.
circular pattern
around the arms
straight at the
center of the loop
Horseshoe Bar magnet
shaped
Magnetic field lines due to Solenoid Fleming’s Left Hand Rule
electromagnet.
A coil of many circular turns of When a current-carrying conductor is placed in
insulated copper wire wrapped an external magnetic field, the conductor
closely in the shape of a cylinder. experiences a force which is mutually
Outside the solenoid: North to perpendicular to both the Magnetic field and to
South the direction of the current flow.
Inside the solenoid: South to North Stretch the thumb, forefinger, and middle finger
Factors: number of turns in the coil, of your left hand perpendicular to each other.
amount of current flowing through
it, radius of coil, Material of core of Forefinger = Magnetic field
the solenoid. direction, Middle finger =
Current direction, Thumb =
Force/motion direction.
Force on a current carrying conductor
in a magnetic field Domestic Circuit
1/100 second in India, i.e. the Potential Difference in
frequency of A.C in India is 50 Hz. India: 220V at 50Hz.
Alternating Current (AC) Direct Current (DC)
AC can travel safely over long DC cannot travel long distances;
distances, even between cities. it loses power.
Frequency is 50 or 60 Hz,
DC has zero frequency.
depending on the country.
Current direction reverses Current flows steadily in one
periodically. direction.
Cheaper then DC generation Expensive then AC generation
