Two identical thin rings each of radius are coaxially placed at a distance

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Two identical thin rings each of radius

R

are coaxially placed at a distance

R

. If the rings have a uniform mass distribution and has mass

m_1

and

m_2

respectively, then the work done in moving a mass

m

from centre of first ring to that of the other is: (A) zero (B)

\frac{Gm(m_1 - m_2)(\sqrt{2} - 1)}{\sqrt{2}R}

(C)

\frac{Gm\sqrt{2}(m_1 + m_2)}{R}

(D)

\frac{Gmm_1(\sqrt{2} + 1)}{m_2R}