A hinge includes a first bracket, a second bracket, a shaft, and first and second interference elements. The shaft is fixed to the first bracket. The second bracket rotationally fit about the shaft. The first interference element is rotationally mounted on the shaft and fixed to the second bracket, and defines two unleveled surfaces at one side. The second interference element is immovably mounted on the shaft beside the first interference element, and defines two unleveled surfaces at one side facing and corresponding to the unleveled surfaces of the first interference element.