If the length of a current-carrying solenoid is doubled keeping the number of turns same and the current is increased to 9 times, the value of magnetic field compared to the original magnetic field B will be:
Correct answer: B. 9/2 B
- A. 2/9 B
- B. 9/2 B
- C. 18 B
- D. 8/18
Explanation
The magnetic field inside a solenoid is given by:B = μ₀nIWhere:B is the magnetic field strengthμ₀ is the permeability of free spacen is the number of turns per unit lengthI is the current flowing through the solenoidIf the length of the solenoid is doubled, the number of turns per unit length (n) will be halved. If the current is increased to 9 times, the magnetic field strength will be:B' = μ₀(n/2)(9I) = (9/2)μ₀nI = (9/2)BTherefore, the magnetic field strength will be 9/2 times the original magnetic field strength.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Electromagnetism
Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.
Practise Electromagnetism
1,176 free Electromagnetism MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Electromagnetism questions
A toroid is?I- A circular ring shape of a coil.II- A solenoid bent in shape of a circle.
Unit of magnetic flux density is
Ammeter lies in _
If two inductors each of inductance L are introduced in a circuit in parallel, the equivalent inductance will be:
Magnetic effect of electric current was first discovered by
Unit of Magnetic Flux is