Question
Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid. Why?
Solution
The magnetic field is given by B=
where, I is the current flowing through the torroid or solenoid.
In a torroid, the magnetic field due to individual wires cancel out everywhere except for the core.
But, in a solenoid magnetic field lines due to individual wires cancel out longitudnally and add up horizontally. Hence, magnetic field lines exist even outside the core.
where, I is the current flowing through the torroid or solenoid.
In a torroid, the magnetic field due to individual wires cancel out everywhere except for the core.
But, in a solenoid magnetic field lines due to individual wires cancel out longitudnally and add up horizontally. Hence, magnetic field lines exist even outside the core.
