The total number of compounds from below when treated with hot KMnO4 giving benzoic acid is:
Identify product [A], [B], and [C] in the following reaction sequence.
The major product of the following reaction is: 
A circular coil of diameter 15 mm having 300 turns is placed in a magnetic field of 30 mT such that the plane of the coil is perpendicular to the direction of the magnetic field. The magnetic field is reduced uniformly to zero in 20 ms and again increased uniformly to 30 mT in 40 ms. If the EMFs induced in the two time intervals are \( e_1 \) and \( e_2 \) respectively, then the value of \( e_1 / e_2 \) is: