Question

The magnetic field inside a long straight current carrying solenoid:

(a) is zero

(b) decreases as we move towards its end.

(c) increases as we move towards its end.

(d) is same at all points.

Answer 1

Correct option is (d) is same at all points.

1. A coil of many circular turns of insulated copper wire wrapped closely in a cylinder's shape is generally known as a solenoid.
2. One end of the solenoid basically acts as a magnetic north pole whereas the other acts as a magnetic south pole.
3. The field lines inside the solenoid are known to be parallel and straight.
4. The magnetic field inside a long straight solenoid-carrying current is generally the same at all points inside a magnetic field.
5. The formula for the field inside the solenoid is B = µ₀IN / L where B is the magnetic field, N is the number of turns in the solenoid, I is the current in the coil, L length of the coil.
6. From the above formula, we can say that solenoid is dependent on the number of turns N, length, and magnetic field.
7. The magnetic field inside the long straight solenoid can be shown as: