# A long solenoid of diameter $0.1\; m$ has $2 \times 10^{4}$ turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to -OA from 4A in 0.05s. If the resistance of the coil is $10 \pi^2 \Omega$ the total charge flowing through the coil during this time is :
$\begin{array}{1 1} (1) 32 \mu C \\ (2) 16 \mu C \\ (3) 32 \mu C \\ (4) 16 \mu C \end{array}$