Question 240: Electromagnetic Induction

Question

When the number of turns in a coil are made 3 times without any change in the length of the coil, its self inductance becomes

Accepted Answer

The self-inductance of a coil is given by the formula:
$$ L = \mu \frac{N^2 A}{l} $$
where:
$L$ is the self-inductance,
$\mu$ is the permeability of the core material,
$N$ is the number of turns in the coil,
$A$ is the cross-sectional area, and
$l$ is the length of the coil.
If the number of turns $N$ is made 3 times greater, with no change in the length of the coil, the new number of turns becomes $3N$. Substituting $3N$ into the formula for self-inductance, we have:
$$ L' = \mu \frac{(3N)^2 A}{l}    = \mu \frac{9N^2 A}{l}    = 9 \cdot \left( \mu \frac{N^2 A}{l} \right)    = 9L $$
Therefore, the self-inductance becomes 9 times its original value.
Answer:
(9) times.

Answer

(9) times

Answer

two times

Answer

three times

Answer

four times

Electromagnetic Induction

When the number of turns in a coil are made 3 times without any change in the length of the coil, its self inductance becomes

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