AP EAMCET Engineering 22 Apr 2019 Shift 1 Paper

The free body diagram of the system is shown below,The magnetic force on the particle is,
F=Bqv
The equilibrium equation for the particle on inclined plane is,
F=mg‌cos‌θ
Bqv=mg‌cos‌θ
v=

mg‌cos‌θ

qB

The time taken to reached at velocity v is,
v=u+at

mg‌cos‌θ

qB

=0+(g‌sin‌θ)t
t=

m‌cot‌θ

qB

Substituting the values, we get
t=

0.02‌cot‌45°

4×10−3×1

t=5 s