Question

I couldn't picture the idea behind the zero magnetic flux outside the solenoid properly. My teacher explained it as

Components of the magnetic field in other directions are cancelled by opposing fields from neighbouring coils. Outside the solenoid the field is also very weak due to this cancellation effect and for a solenoid which is long in comparison to its diameter, the field is very close to zero.

But I didn't understand anything at all. First he said about the components of magnetic field in other direction being cancelled by magnetic field, but didnt further explain and said nothing to support his argument. If somebody has some simple, intuitive way of understanding this phenomenon then please explain it.

Answer 1

The zero magnetic flux outside a solenoid is due to the cancellation of magnetic fields from neighboring coils in directions other than the axis of the solenoid, resulting in a weak field.

Step-by-step explanation:

The idea behind the zero magnetic flux outside a solenoid can be explained using the concept of cancellation of magnetic fields. Inside the solenoid, the magnetic field is very uniform due to the alignment of the magnetic field lines from each individual coil. Therefore, the components of the magnetic field in other directions add up and result in a strong magnetic field.

However, outside the solenoid, the magnetic field from each coil cancels out the magnetic field from the neighboring coils in directions other than the axis of the solenoid. As a result, the field outside the solenoid is very weak and close to zero.