The corecivity of a bar magnet is 100 A/m. It is to be demagnetised by placing it inside a solenoid of length 100 cm and number of turns 50. The current flowing the solenoid will be-

4A 2A 1A Zero

2A

$H = nI$ $ I = \frac{H}{n} = \frac{100}{50} = 2A$