Definitions [4]
Define magnetic dipole moment.
The magnetic dipole moment is defined as the product of its pole strength and magnetic length.
`vec"P" = "q"_"m"vec"d"`
Define the following term:
Ferromagnetism
Ferromagnetism is defined as the phenomenon in which substances, such as iron, cobalt and nickel, are strongly attracted by a magnetic field. Such substances are called ferromagnetic substances.
Define the magnetic effect of electric current.
A current-carrying conductor is always associated with a magnetic field around it is called the magnetic effect of current. It was first discovered by Hans Christian Oersted in 1820.
Define ampere.
Current passed through each of the two infinitely long parallel straight conductors kept at a distance of one meter apart in vacuum causes each conductor to experience a force of 2 × 10-7 newton per meter length of the conductor.
Key Points
- Electric current creates a magnetic field, shown by compass needle deflection.
- Oersted discovered the link between electricity and magnetism in 1820.
- Reversing current changes the direction of the magnetic field.
- Iron filings form circular patterns, showing magnetic field lines around the wire.
- Magnetic field strength increases with current and decreases with distance.
Concepts [11]
- Concept of Magnetism
- Coulomb’s Inverse Square Law of Magnetism
- Torque Acting on a Bar Magnet in Uniform Magnetic Field
- Properties of Solids: Magnetic Properties
- Classification of Magnetic Materials
- Hysteresis: Retentivity and Coercivity
- Magnetic Effect of Electric Current
- Biot-Savart Law
- Ampere’s Circuital Law
- Lorentz Force
- Torque on a Current-Loop in a Uniform Magnetic Field
