The direction of the magnetic field around a wire depends on
the direction of the current flowing through the wire. When you
change the direction of the current in the wire, the direction of the
magnetic field around it also changes direction.
The current in every electric cord in your house changes its direction
120 times every second. So the magnetic field around every electric
cord in your house also changes its direction 120 times every second.
<h2>Answer : </h2>
Newton's Third law of motion states :
" Every action has an equal and opposite reaction "
i.e If a force is applied by an object A on another object B then that object B also exerts a foce on object A, that is of same magnitude and opposite direction to the force applied by object A.
Ex - A book on a table exerts gravitational force on the table and table exerts back a normal force on the book.
Answer:

Explanation:
Let
be the polar angle of −3i + j. We can find it using the formula as follows :

So, the required polar angle is
.
Speedometer tells you how fast your going and odometer is how many miles u drive