Question

what condition is the magnitude of average velocity of an object is equal to its average speed

Answer 1

Average velocity would be equal to average speed when the total distance travelled equals the net displacement of a particle. This happens when a particle moves along a straight line in a fixed direction.

Answer 2

Average speed and average velocity can only be equal if the total displacement is equal to the total distance

$average \: v \: = \frac{total \: displacement}{total \: time}$

$average \: speed \: = \frac{total \: distance}{total \: time}$

I hope this helps ( ╹▽╹ )