3when a bar magnet moves in a wire loop,
what does the wire loop produce?
a. an electric current
b. electrical resistance
c. ferromagnetic elements
d. magnetic domains

   A. an electric current

When a bar magnet moves inside a wire loop it produces electric current.

Explanation:

Prior to the introduction of the magnet inside the wire loop, the loop doesn’t have any current. When the bar magnet is introduced inside the loop, there develops  a magnetic flux.

When the magnet is moved inside the wire loop the magnetic flux associated with the loop changes and this change induces an electric current.  This happens due to electromagnetic induction whereby a change in magnetic flux induces a current.

The movement of the magnet inside the coil increases and decreases its magnetic flux and this change produces an electric current which can be measured by connecting the coil to a galvanometer.

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

think its the third option