A solenoid with 100 turns per metre carries a current of 1.2 A. The magnetic intensity inside the solenoid is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \( 120\,\mathrm{A\,m^{-1}} \)
The magnetic intensity \( H \) inside a long solenoid is the number of turns per unit length multiplied by the current. It depends only on n and I, not on the material of the core.
\( H = nI \)
\( H = 100\,\mathrm{m^{-1}}\times1.2\,\mathrm{A} = 120\,\mathrm{A\,m^{-1}} \)
Note: NTA picked this question from an NCERT (2026-27) example and changed the figures. Do not ignore NCERT while practising numericals.
NCERT (2026-27):
Magnetisation and Magnetic Intensity – …
