i am working on a tandem rotor using EDF(electric ducted fan). I am not sure about the direction of rotation of the fan(to cancel out the torque effect). Should the rotor rotate in same direction of opposite direction(when viewed form above).
          Thanks in advance.

Can you post an illustration of what you are trying to do ?  Just use MS Paint, or just draw on a piece of paper and take a picture of it and post it here.

i have read that the rotors should rotate in opposite direction to cancel the torque effect.
i cannot understand that.
This is what i think. dont know whether it is right or wrong.

this might help you, its rotor digram of CH4.

This video should do it, right ?

thank u very much for replaying. Can anybody tell me the direction of net torque