NEET Exam Model Paper 7

Let F’ be the friction on the ring towards right, a its linear acceleration and α the angular acceleration about center of mass. Point of contact P is momentarily as rest i.e., ring will rotate about P.
α=

τp

Ip

=

F(2R)

2MR2

=

F

MR

now F+F′=Ma=MRα=F
or F′=0