Rapid Revision: Magnetism

Types of Natural Magnetism

• Earth's own magnetism
• Metals: Nickel, Cobalt
• Magnetic effect generated by moving charge

Oersted's Experiment

• Current carrying circuit and magnetic needle
• Creation of magnetic field by current

Bar Magnet

• Bar magnet and horseshoe magnet
• North and South poles

Magnetic Field

• Area around a magnet
• Magnetic field of lines: from North to South
• Properties: Lines do not intersect

Maxwell's Right Hand Thumb Rule

• Thumb in the direction of current
• Direction of magnetic field: curl of fingers
• Directions in concentric circles for straight wire

Current Carrying Loop

• Direction of magnetic field in loop
• Solenoid: many loops

Properties of Solenoid

• Straight direction of magnetic field
• Similar to an electromagnet

Fleming's Left Hand Rule

• Thumb: Direction of force
• Index finger: Magnetic field
• Middle finger: Current

Domestic Circuit

• Difference between AC and DC current
• Types of wires: Live, Neutral, Earth

Short Circuit and Overloading

• Short circuit: Low resistance, high current
• Overloading: Current exceeding safety limit
• Function of electrical fuse

Question

• Solve the given question and discuss in the comments.

These notes summarize important aspects of magnetism that may aid in exam preparation.