🎯 Knowledge Check
Physics — Magnetic Effects Of Electric Current
Frequently Asked Questions
The region around a magnet or current-carrying conductor within which its magnetic influence can be felt is called a magnetic field.
Imaginary lines that represent the direction and strength of the magnetic field. They emerge from the North pole and enter the South pole.
Outside a magnet: North ? South. Inside the magnet: South ? North, forming closed loops.
A stronger magnetic field.
If we hold the current-carrying conductor with the right hand such that the thumb points in the direction of current, then the curled fingers show the direction of magnetic field lines.
Concentric circles formed around the conductor; strength increases with increase in current and decreases with distance.
\( B \propto \dfrac{I}{r} \), where I is current and r is distance.
The direction of the magnetic field also reverses.
A long coil of closely spaced circular turns of insulated wire.
It produces a uniform strong magnetic field inside it, with a defined North and South pole.
A temporary magnet formed when current passes through a coil wrapped around a soft iron core.
Used in electric bells, cranes, speakers, relays, magnetic locks, etc.
A device that converts electrical energy to mechanical energy.
On the magnetic effect of electric current and force on a current-carrying conductor.
If the thumb, forefinger, and middle finger of the left hand are placed perpendicular: Forefinger = magnetic field, Middle finger = current, Thumb = direction of force.