Correct Answer - Option 1 : Both free and bound currents
Concept:
Magnetized substance:
- These are substances that get attracted to magnets.
- A few of the magnetic substances are - iron, steel, cobalt and nickel.
Difference b/w free current and bound current:
| Free current (If) |
Bound current (Ib) |
| A current which produces due to the movement of a free electron. |
Current produce due to spin and orbital motion of electrons in an atom of substance.
|
| It can be measured with the help of an ammeter.
|
Bound current can not be measure by an ammeter. |
| The Source of this current can be battery or emf. |
It is a current which introduces to take into account a magnetization sample. |
| This can produce a magnetic effect, heating effect or chemical effect depending upon whether it is DC or AC. |
This current does not produce any heating effect. it is also known as magnetization current. |
Explanation:
- When we put a substance in a magnetic field, the substance gets magnetized and a bound current is produced.
- The bound current itself then produces a magnetic field, so there are now two fields, field due to bound current and free current.
\(\oint \vec{B}.\vec{dl} = \mu _0(I_b + I_f)\)
Hence, from the above discussion, we can conclude that cause of the magnetic field within a magnetized substance is both free and bound current.
