List of top Physics Questions on Uniform Circular Motion asked in WBJEE

A particle is moving in the $x$-$y$ plane according to $r = b \cos \omega t \hat{i} + b \sin \omega t \hat{j}$. Where $\omega$ is constant. Which of the following statement(s) is/are true?
The coercivity of a small magnet where the ferromagnet gets demagnetised is 3 x 103 Am–1. The current required to be passed in a solenoid of length 10 cm and number of turns 100, so that the magnet gets demagnetised when inside the solenoid, is