Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A deflection magnetometer is placed with its arm along the east-west direction (tan A position) and a short bar magnet is placed symmetrically along its axis at some distance with its north pole pointing towards east. In this position the needle of the magnetometer shows a deflection of 60°. If we double the distance of the bar magnet, then the deflection will be
PhysicsMagnetic Properties of MatterJEE Main
Options:
  • A sin-138
  • B cos-138
  • C tan-138
  • D cot-138
Solution:
2373 Upvotes Verified Answer
The correct answer is: tan-138
For a short bar magnet in tan A position,

μ04π2Md3=H tanθ             ...(i)

When distance is doubled, then new deflection θ is given by,

μ04π2M2d3=H tanθ' ....(ii)

    tan  θ tan θ=18

        tan θ=taθ8=tan 60°8=38

        θ=tan-138

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.