Magnetic Effects of Electric Current - Vocabulary Flashcards

Vocabulary flashcards generated from Chapter 12 lecture notes covering electromagnetism, magnetic fields, rules of direction, circuit safety, and medical applications.

Hans Christian Oersted

A 19th-century scientist who discovered in 1820 that an electric current deflects a nearby compass needle, demonstrating that electricity and magnetism are related phenomena.

Magnetic Field

The region surrounding a magnet in which its magnetic force can be detected, possessing both magnitude and direction.

Magnetic Field Lines

Closed continuous curves representing the path along which a hypothetical free north pole would move in a magnetic field, emerging from the north pole and merging at the south pole.

Right-Hand Thumb Rule

A rule stating that if a current-carrying straight conductor is held in the right hand with the thumb pointing in the direction of current, the wrapped fingers show the direction of magnetic field lines.

Solenoid

A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder.

Electromagnet

A temporary magnet created by placing a core of magnetic material, such as soft iron, inside a current-carrying solenoid coil.

Fleming's Left-Hand Rule

A rule determining the direction of force on a conductor, stating that if the thumb, forefinger, and middle finger of the left hand are held mutually perpendicular with the forefinger pointing in the magnetic field direction and middle finger in current direction, the thumb points in the direction of motion or force.

Live Wire

The positive supply wire in domestic electric circuits, covered with red insulation and maintained at a potential difference of $220\,V$ relative to the neutral wire in India.

Neutral Wire

The negative supply wire in domestic electric circuits, covered with black insulation.

Earth Wire

A safety wire with green insulation connected to a metal plate deep in the earth near a house, providing a low-resistance path to discharge current leakages safely to the ground.

Short-Circuiting

An abrupt and heavy increase in current that occurs when a live wire and a neutral wire come into direct contact due to damaged insulation or appliance faults.

Overloading

A condition in an electric circuit where current exceeds the circuit's rated capacity, caused by connecting too many appliances to a single socket, direct contact of live and neutral wires, or a sudden voltage hike.

Electric Fuse

A safety device in electric circuits that protects appliances and wiring by melting due to Joule heating when excess current flows, breaking the circuit.

Magnetic Resonance Imaging (MRI)

A medical diagnostic technique that generates images of internal body parts using the magnetic fields naturally produced by ion currents in organs like the heart and brain.