Answer:

Step-by-step explanation:
Given that,
Charge, q = 0.250 μC
It is released from a height of 30 cm or 0.03 m
The magnetic field strength is 1.50 T.
First we find the velocity using the conservation of energy as follows :

Now, the magnetic force is given by :

So, the magnetic force is
. Since, the bob is at the lowest point, the direction of the magnetic force at the lowest point is upward.