Question

Regarding self-inductance: \( \text{A} \): The self-inductance of the coil depends on its geometry.
\( \text{B} \): Self-inductance does not depend on the permeability of the medium.
\( \text{C} \): Self-induced e.m.f. opposes any change in the current in a circuit.
\( \text{D} \): Self-inductance is the electromagnetic analogue of mass in mechanics.
\( \text{E} \): Work needs to be done against self-induced e.m.f. in establishing the current.
Choose the correct answer from the options given below:

• A. A, B, C, D only
• B. A, C, D, E only
• C. A, B, C, E only
• D. B, C, D, E only

Hint:

Self-inductance depends on factors such as the coil's geometry, the medium's permeability, and the number of turns in the coil. Remember that it is directly related to the opposition of current change.

Answer 1

The Correct Option is B

To identify accurate statements about self-inductance, each assertion requires examination:

1. Statement A: The self-inductance of a coil is determined by its geometry.
   Self-inductance is influenced by factors such as the number of turns, cross-sectional area, and length of the coil. These are all geometric properties, confirming that the coil's geometry dictates its self-inductance. Consequently, this statement is accurate.
2. Statement B: Self-inductance is independent of the medium's permeability.
   This statement is inaccurate. Self-inductance is directly proportional to the permeability of the medium enclosing the coil. A higher permeability results in greater magnetic flux for a given current, thereby increasing self-inductance.
3. Statement C: The self-induced electromotive force (e.m.f.) opposes any alteration in the circuit's current.
   Lenz's Law dictates that the self-induced e.m.f. in a coil resists the change in current that generates it, referred to as the back e.m.f. Therefore, this statement is accurate.
4. Statement D: Self-inductance serves as the electromagnetic equivalent of mass in mechanics.
   Mass in mechanics impedes changes in velocity due to inertia. In electrical circuits, self-inductance impedes changes in current. Thus, self-inductance can be considered analogous to mass. This statement is accurate.
5. Statement E: Work is expended against the self-induced e.m.f. when establishing the current.
   When current changes in a coil, work must be performed to counteract the back e.m.f. produced by the self-inductance. Accordingly, this statement is also accurate.

Based on the preceding analysis, statements A, C, D, and E are correct. Therefore, the definitive answer is:

A, C, D, E only