MHT CET202210 Aug 2022Evening ShiftPhysicsElectromagnetic InductionActual
Self-induction of a solenoid cannot be increased by
Options
- Adecreasing its length
- Bincreasing its area of cross-section
- Cincreasing the current through it
- Dincreasing the number of turns in it
Correct answer
C. increasing the current through it
Step-by-step solution
For a solinoid magnetic field at the center is: B= ₀ ( N l ) I , Total magnetic self flux is: =B A N= ₀ ( N l ) I A N According to the definition of magnetic flux and coefficient of self induction: =L I On comparing the above two expressions, the self-induction of a long solenoid is given by L= ₀ N^2 L where, N= number of truns, L= Length and A= cross - sectional area. Therefore, the self-induction of a long solenoid does not depend upon the current flowing through it.