B = 0.018 T Ans,
Since, it is moving in a circular path, thus, centripetal force will act on it i.e.
F =

where, m is the mass of the object, v is the velocity and r is the radius of circular path.
And, since a positive charge is moving, it will create magnetic force which is equal to F = qvB
where q is the charge, v is the velocity of the particle and B is the magnetic field.
Now, the two forces will be equal,
i.e.

= qvB
⇒

= qB
⇒B =

<span>putting the values, we get,
</span>
use q = 1.6 * 10^ -19
⇒ B = 0.018 T
Answer:
Option (C) is correct.
Explanation:
Assuming that the hiker starts walking from the origin O as shown in the figure.
First, he walks 200 m west to point A (say), then he walks 100 m north to the final point B (say) as shown in the figure.
The final point B is in the north-west direction, therefore, the resulting point is in the north-west direction.
Hence, option (C) is correct.
Gravity is a force because it pulls down on objects.
Fair enough, but you'll have to tell us the volume of the bar first.