Q no. 2...Answer is A
Q.2. An infinite number of uniform discs are pivoted at their respective centres and arrange in such a manner that centres of all the discs are at the same horizontal level. Radius of biggest disc is R and successive discs have radii 1/$3^{rd}$ of radius of disc to its left. A rod having same mass as the mass of largest disc is placed over the discs, touching all of them. There is no friction between discs but friction is sufficient between rod and discs, so that rod does not slip. Acceleration of rod is

(A) $\frac{8g}{25}$
(B) $\frac{3g}{25}$
(C) $\frac{g}{25}$
(D) $\frac{g}{50}$