Which one of the following statements regarding a current-carrying solenoid is not correct?

This question was previously asked in
NDA 02/2022 General Ability Test Official Paper (Held On 4 Sep 2022)
View all NDA Papers >
  1. The magnetic field inside the solenoid is uniform.
  2. The current-carrying solenoid behaves like a bar magnet.
  3. The magnetic field inside the solenoid increases with increase in current.
  4. If a soft iron bar is inserted inside the solenoid, the magnetic field remains the same. 

Answer (Detailed Solution Below)

Option 4 : If a soft iron bar is inserted inside the solenoid, the magnetic field remains the same. 
Free
BSF HC RO/RM All India Mega Live Test
5.4 K Users
100 Questions 200 Marks 120 Mins

Detailed Solution

Download Solution PDF

Concept:

A solenoid is a wire wound closely in the form of a helix

  • when a soft iron rod is inserted inside a magnetic field it magnetizes the iron rod. 
  • A current-carrying solenoid produces a similar pattern of the magnetic field as a bar magnet.
  • The magnet field lines inside the solenoid are in the form of parallel straight lines.

F1 Madhuri Defence 20.09.2022 D1

Explanation:

  • A current carrying solenoid produces its own magnetic field inside and outside the solenoid
  • So, when a soft iron rod is placed inside a solenoid then due to the magnetic field of the solenoid iron rod gets magnetized that's why it increases the magnetic field inside the solenoid

 Additional Information

The magnetic field inside a solenoid, B = μ0ni

\(n= \frac{N}{L}\)

Where, μo is the permeability constant = 1.26 × 10−6 T/m,

N is the number of turns in the solenoid,

I is the current passing through the coil,

L is the coil length.

Latest NDA Updates

Last updated on May 30, 2025

->UPSC has released UPSC NDA 2 Notification on 28th May 2025 announcing the NDA 2 vacancies.

-> A total of 406 vacancies have been announced for NDA 2 Exam 2025.

->The NDA exam date 2025 has been announced for cycle 2. The written examination will be held on 14th September 2025.

-> Earlier, the UPSC NDA 1 Exam Result has been released on the official website.

-> The selection process for the NDA exam includes a Written Exam and SSB Interview.

-> Candidates who get successful selection under UPSC NDA will get a salary range between Rs. 15,600 to Rs. 39,100. 

-> Candidates must go through the NDA previous year question paper. Attempting the NDA mock test is also essential. 

More Moving Charges and Magnetism Questions

Get Free Access Now
Hot Links: teen patti win teen patti gold download teen patti go teen patti master new version