CBSE 2023 · Region 4 · Set 1 · Q27 · 3 marks
(a)The figure shows the variation of induced emf as a function of rate of change of current for two identical solenoids X and Y . One is air cored and the other is iron cored. Which one of them is iron cored? Why ?
(b)Obtain an expression for self-inductance of a long solenoid of length L and cross-sectional area A having N turns.
(a)
The figure shows the variation of induced emf as a function of rate of change of current for two identical solenoids X and Y . One is air cored and the other is iron cored. Which one of them is iron cored? Why ?
(b)
Obtain an expression for self-inductance of a long solenoid of length L and cross-sectional area A having N turns.
Marking-scheme solution
(a)
X is iron cored.
Reason- From the graph-
\[\text { Slope of the graph }=\frac{\varepsilon}{|d I / d t|}=L
\]
Slope of X is more than that of Y. Hence X is iron cored because Inductance of iron cored coil is more than that of air cored coil.
(b)
Magnetic field due to solenoid (axis)
\[B=\frac{\mu_{0} N I}{l}
\]
Magnetic flux through the solenoid
\[\phi_{B}=N \phi=\frac{\mu_{0} N^{2} A}{L} I
\]
Since self-inductance \(\displaystyle =\frac{\phi_{B}}{I}\)
\[=\frac{\mu_{0} N^{2} A}{L}
\]
Electromagnetic InductionInductanceAnalyseshort_answermedium
More from Electromagnetic Induction
- Assertion: The mutual inductance between two coils is maximum when the coils are wound on each other. Reason…2024 · asked 3×
- In the process of charging of a capacitor, the current produced between the plates of the capacitor is:2023 · asked 3×
- A vertically held bar magnet is dropped along the axis of a copper ring having a cut as shown in the diagram.…2025 · asked 3×
- The direction of induced current in the loop abc is:2023 · asked 3×
- (i) Define self-inductance of a coil. Derive the expression for the energy required to build up a current I…2025 · asked 3×
- Two coils C 1 and C 2 are placed close to each other. The magnetic flux φ 2 linked with the coil C 2 varies…2023 · asked 3×
- Assertion: Induced emf produced in a coil will be more when the magnetic flux linked with the coil is more.…2026 · asked 3×
- (i) State Lenz's law and explain how this law is a consequence of conservation of energy principle. (ii) A…2025 · asked 3×
CBSE Class 12 Physics past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.