# A long solenoid of diameter 0.1m has 2×104 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 0A from 4A in 0.05s. If the resistance of the coil is 10π2Ω the total charge flowing through the coil during this time is.

A long solenoid of diameter 0.1m has 2×10<sup>4</sup> 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 0A from 4A in 0.05s. If the resistance of the coil is 10π<sup>2</sup>Ω the total charge flowing through the coil during this time is.

1. 32 πμC
2. 32 μC
3. 16 πC
4. 16 πμC

The correct option is ii. 32 μC