Question

The opposition that the magnetic circuit offers to magnetic flux is called

• A. Permeance
• B. Conductance
• C. Reluctance
• D. Transmittance

Hint:

Remember the magnetic-electric circuit analogy: - MMF $\rightarrow$ EMF (Voltage) - Magnetic Flux $\rightarrow$ Electric Current - Reluctance $\rightarrow$ Resistance.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
A magnetic circuit is a closed path through which magnetic flux flows.
There is a close mathematical analogy between magnetic circuits and electrical circuits.

Step 2: Detailed Explanation:
In an electrical circuit, the opposition to the flow of electric current is called resistance ($R = \frac{V}{I}$).
Analogously, in a magnetic circuit, the opposition to the setup of magnetic flux is called Reluctance ($S$).
Reluctance is defined as the ratio of magnetomotive force (MMF) to the magnetic flux ($\Phi$):
\[ S = \frac{\text{MMF}}{\Phi} \]
Reluctance depends on the length of the magnetic path, the cross-sectional area, and the magnetic permeability of the material.
- Permeance is the reciprocal of reluctance, representing the ease with which magnetic flux can be established.
- Conductance is an electrical property representing the ease of current flow.
Therefore, reluctance is the term for the opposition offered to magnetic flux.

Step 3: Final Answer
The correct option is (C).