Electro-magnetism notes for ICSE Class 10 Physics
1. Introduction to Electromagnetism
• Electromagnetism: The study of the interaction between
electric currents and magnetic fields.
• Key Discoveries:
o Oersted's Experiment (1820): Demonstrated that an
electric current produces a magnetic field around it.
o Faraday’s Law of Electromagnetic Induction (1831):
Induced current in a conductor due to a changing
magnetic field.
2. Magnetic Field and Magnetic Field Lines
• Magnetic Field:
o Region around a magnet or current-carrying conductor
where a magnetic force is experienced.
o Represented by magnetic field lines.
• Magnetic Field Lines:
o Imaginary lines that represent the direction and strength
of the magnetic field.
o Properties:
▪ Emerge from the north pole and enter the south
pole of a magnet.
▪ Never intersect.
▪ Closer lines indicate stronger fields.
3. Magnetic Field Around a Current-Carrying Conductor
, • Straight Conductor:
o Magnetic field lines are concentric circles centered
around the conductor.
o Right-Hand Thumb Rule:
▪ If the thumb of your right hand points in the
direction of the current, the curled fingers indicate
the direction of the magnetic field.
• Circular Loop:
o Magnetic field at the center of the loop is perpendicular
to the plane of the loop.
o Increasing the number of loops or current strengthens
the magnetic field.
• Solenoid:
o A solenoid is a coil of wire with many turns.
o Magnetic field inside a solenoid is uniform and resembles
that of a bar magnet.
o Formula for magnetic field inside a solenoid: B=μ0nIB =
\mu_0 n I Where:
▪ BB: Magnetic field strength,
▪ μ0\mu_0: Permeability of free space
(4π×10−7 T⋅m/A4\pi \times 10^{-7} \, T·m/A),
▪ nn: Number of turns per unit length,
▪ II: Current through the solenoid.
4. Electromagnetic Induction
• Definition: The process of inducing an electric current in a
conductor when it is placed in a changing magnetic field.
• Faraday’s Laws of Electromagnetic Induction:
1. Introduction to Electromagnetism
• Electromagnetism: The study of the interaction between
electric currents and magnetic fields.
• Key Discoveries:
o Oersted's Experiment (1820): Demonstrated that an
electric current produces a magnetic field around it.
o Faraday’s Law of Electromagnetic Induction (1831):
Induced current in a conductor due to a changing
magnetic field.
2. Magnetic Field and Magnetic Field Lines
• Magnetic Field:
o Region around a magnet or current-carrying conductor
where a magnetic force is experienced.
o Represented by magnetic field lines.
• Magnetic Field Lines:
o Imaginary lines that represent the direction and strength
of the magnetic field.
o Properties:
▪ Emerge from the north pole and enter the south
pole of a magnet.
▪ Never intersect.
▪ Closer lines indicate stronger fields.
3. Magnetic Field Around a Current-Carrying Conductor
, • Straight Conductor:
o Magnetic field lines are concentric circles centered
around the conductor.
o Right-Hand Thumb Rule:
▪ If the thumb of your right hand points in the
direction of the current, the curled fingers indicate
the direction of the magnetic field.
• Circular Loop:
o Magnetic field at the center of the loop is perpendicular
to the plane of the loop.
o Increasing the number of loops or current strengthens
the magnetic field.
• Solenoid:
o A solenoid is a coil of wire with many turns.
o Magnetic field inside a solenoid is uniform and resembles
that of a bar magnet.
o Formula for magnetic field inside a solenoid: B=μ0nIB =
\mu_0 n I Where:
▪ BB: Magnetic field strength,
▪ μ0\mu_0: Permeability of free space
(4π×10−7 T⋅m/A4\pi \times 10^{-7} \, T·m/A),
▪ nn: Number of turns per unit length,
▪ II: Current through the solenoid.
4. Electromagnetic Induction
• Definition: The process of inducing an electric current in a
conductor when it is placed in a changing magnetic field.
• Faraday’s Laws of Electromagnetic Induction:
