You have designed a little wheeled mobile robot and would like to compute the power drawn by themotors when the robot moves on different surfaces.
attaching wires to the robot will impede itsmotion so you want to determine a way to measure current going to the motors without wires. youare able to find the no load speed of the motor (920 rpm) and the stall torque (35 g-cm) whenoperated at 3v.

a. you run the robot with its wheels spinning in air and find the current required to overcomefriction in the motor and robot (inl) is 40 ma. what is the torque required to overcome thisfriction?

b. you are able to measure the wheel speed of the robot by calculating the robots speed andmaking sure that the wheels do not slip. if the wheels are rotating at 400 rpm at the same 3v, what is the motor current draw?