Question:

While keeping area of cross-section of a solenoid same, the number of turns and length of solenoid one both doubled. The self inductance of the coil will be

Updated On: Jul 2, 2022
  • halved
  • doubted
  • $ \frac{1}{4} $ times the original value
  • unaffected
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

The magnetic field inside the solenoid $B=\mu_{0} n i $ Flux, $\phi=B n l A=\mu_{0} n^{2} I A i$ where, $A=$ area of cross-section. As, $ L=\frac{\phi}{L}=\mu_{0} n^{2} l A=\frac{\mu_{0} N^{2}}{l} A$ Here, $n=$ number of turns per unit length $=N / l$ When $N$ and $l$ are doubled, then $L'=\mu_{0} \frac{(2 N)^{2}}{2l} A$ $=2 \mu_{0} \frac{N^{2} A}{l}=2 L$
Was this answer helpful?
0
0

Questions Asked in AIIMS exam

View More Questions

Concepts Used:

Inductance

Inductance is a key parameter in electrical and electronic circuit designs. Like resistance and capacitance, it is a basic electrical measurement that affects all circuits to some degree.

Inductance is used in many areas of electrical and electronic systems and circuits. The electronic components can be in a variety of forms and may be called by a variety of names: coils, inductors, chokes, transformers, . . . Each of these may also have a variety of different variants: with and without cores and the core materials may be of different types.

There are two ways in which inductance is used:

  • Self-inductance: Self-inductance is the property of a circuit, often a coil, whereby a change in current causes a change in voltage in that circuit due to the magnetic effect of caused by the current flow. It can be seen that self-inductance applies to a single circuit - in other words it is an inductance, typically within a single coil. This effect is used in single coils or chokes.
  • Mutual-inductance: Mutual inductance is an inductive effect where a change in current in one circuit causes a change in voltage across a second circuit as a result of a magnetic field that links both circuits. This effect is used in transformers.