This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Physiology
Weber-Fechner law related to: 
Select and explain. 
A. Number of nerve Fibers, B. Number of muscle Fibers, C. Number of stimulus, D. Intensity of stimulus
D: Intensity of stimulus
Answer: D: Intensity of stimulus 
Explanation: Weber Fechner law: S = K x Log (I) S = sensory perception at coex K = constant (I) = intensity of stimulus at the periphery Perception felt about the intensity of stimulus changes with logarithmic scale of the actual intensity applied at the periphery. Related: Steven's power law S = K x (I)N Sensation felt is propoional to the nth power of intensity of stimulus applied i.e. perception changes as a power function of intensity.