Question

A coil has \( N \) turns and current passes through it as \( I \) ampere, then we obtain \( L \) Henry of self-inductance. Now if the current changes to 5I, then the new self-inductance will be 

Hint:

Self-inductance (\( L \)) is a property of a coil that depends on its number of turns and dimensions, not on the amount of current passing through it.

Answer 1

Step 1: Understanding Self-Inductance 
Self-inductance (\( L \)) of a coil is given by: \[ L = \frac{N \Phi}{I} \] where:
- \( L \) is the self-inductance (Henry),
- \( N \) is the number of turns,
- \( \Phi \) is the magnetic flux linked with the coil,
- \( I \) is the current passing through the coil. 
Step 2: Effect of Changing Current on Self-Inductance 
- Self-inductance \( L \) depends on the geometry and material of the coil, not on the current passing through it.
- When current increases from \( I \) to \( 5I \), the magnetic flux (\(\Phi\)) will increase proportionally, but the self-inductance remains constant. 
Step 3: Conclusion 
Since self-inductance is independent of current, the new self-inductance remains: \[ L \] Thus, the self-inductance remains unchanged at \( L \).