A pivoted magnetic needle of length 2l and pole strength 'm' is at rest in magnetic meridian. It is held in equilibrium at an angle θ to a magnetic induction field BH by applying a force F at a distance 'r' from the pivot along a direction perpendicular to the field, then F=?
see full answer
Your Exam Success, Personally Taken Care Of
1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya
a
F=(2l)mBHtanθr
b
F=r2lmBHtanθ
c
F=mBHtanθ2r
d
F=2rmBHtanθ
answer is A.
(Unlock A.I Detailed Solution for FREE)
Best Courses for You
JEE
NEET
Foundation JEE
Foundation NEET
CBSE
Detailed Solution
In equilibrium, torque due to F is balanced by torque due to BH ∴τF=τBH ⇒ ( Fcosθ)r=MBHsinθ ⇒F=MBHsinθcosθ×1r ⇒F=m(2l)BHtanθr
A pivoted magnetic needle of length 2l and pole strength 'm' is at rest in magnetic meridian. It is held in equilibrium at an angle θ to a magnetic induction field BH by applying a force F at a distance 'r' from the pivot along a direction perpendicular to the field, then F=?