What will be the motion of quadcopter when all the propellers start rotating in clockwise direction in mid air?

If all the propellers of a quadcopter start rotating in the same direction (in this case, clockwise), the quadcopter will not be able to maintain stable flight. This is because the rotation of the propellers in the same direction will generate a torque, or rotational force, causing the quadcopter to spin in the opposite direction (in this case, counterclockwise) due to Newton's third law of motion (for every action, there is an equal and opposite reaction).

In a typical quadcopter design, two of the propellers rotate clockwise and the other two rotate counterclockwise. This arrangement allows the torques generated by the propellers to cancel each other out, enabling the quadcopter to maintain stable flight.

So, if all propellers were to rotate in the same direction, the quadcopter would spin uncontrollably in the opposite direction. It would not be able to move forward, backward, or to the sides effectively, and it would be very difficult, if not impossible, to control its altitude.