KCET 2023 Physics Solved Paper

A positively charged particle of mass m is passed through a velocity selector. It moves horizontally rightward without deviation along the line y=‌

2 mv

qB

with a speed v. The electric field is vertically downwards and magnetic field is into the plane of the paper. Now, the electric field is switched off at t=0. The angular momentum of the charged particle about origin O at t=‌

πm

qB

is