দুটি সমকেন্দ্রিক গোলাকার পরিবাহী শেলের ব্যাসার্ধ হল `r_(1) এবং r_(2)(gt r_(1))`।

If r/(r_(1))=(r_(2))/(r_(3)) , then

r+r_(3)+r_(1)-r_(2)=

Prove that (r_(1)+r_(2))/(1+cos C)=2R

show that r_(2)r_(3) +r_(3) r_(1)+ r _(1) r_(2)=s^(2)

In a triangle, if r_(1) gt r_(2) gt r_(3), then show a gtb gt c.

Two concentric spherical shells have masses m_(1) and m_(2) and radii r_(1) and r_(2) (r_(2) gt r_(1)) . What is the force exerted by this system on a particle of mass m_(3) . If it is placed at a distance r(r_(1) lt r lt r_(2)) from the centre ?

Define the term 'mutual inductance' between the two coils. Obtain the expression for mutual inductance of a pair of long coaxial solenoids each of I and radii r_(1) and r_(2)(r_(2)gt gt r_(1)) . Total number of solenoids are N_(1) and N_(2) respectively.

Consider two concentric spherical metal shells of radii r_(1) and r_(2) (r_(2) gt r_(1)) . If the outer shell has a charge q and the inner one is grounded, then the charge on the inner shell is