Magnetic Field Strength
Physics: Cambridge International GCSE Supplement, topic 4.14.1
Magnetic Field Strength
The closer together magnetic field lines are, the stronger the magnetic field.
For a straight wire
- For a straight wire carrying a current, the magnetic field is strongest at the points closest to the wire, and weakest further away from the wire.
%20-%20Field%20around%20solenoid-min,w_800.jpg)
For a coil of wire (solenoid)
- For a solenoid (coil of wire), the magnetic field inside the solenoid is strong and uniform.
- Outside of the solenoid the magnetic field decreases in strength the further away it is from the solenoid.
Changing the magnetic field
- For both solenoids and straight wires, increasing the size of the current increases the strength of the magnetic field, and flipping the direction of the current flips the direction of the magnetic field lines.
Test yourself on Magnetic Field Strength
Where is a magnetic field around a wire strongest?
Select the correct statement in each pair.