I have attached the image of the clipper circuit below. When Vin is positive the diode is reverse biased and the output and input are at the same loop. When Vin is negative the diode is forward biased and Vo=0. My problem is finding the sign of the output, although I know that Vo and Vin are numerically equal. The output waveform of this clipper circuit shows that Vo= Vin. My question is why. If we consider the loop containing Vo and Vin, they must be of opposite polarity so that the sum of the voltages around the loop is zero. If they are equal then the sum of all voltages around the loop is not zero. i have failed an exam just because of this.The waveform i get is the exact opposite of the real one beacause i think that Vo=-Vin. We are being taught basic electronics and dc circuits at the same time, and i think dc and ac circuits must be a prerequisite of this electronics course. Is this ok.