OBJECT

Kevin touches four objects, I, II, III, and IV. He makes the following conclusions: Object I is hot. Object II is vibrating. Object III is cold. Object IV is sticky. Among the given objects, the object producing sound is

When sepration between the central maxima of the two object is less than the separation between central maximum of first object and the first minima of the first object and the first minima of the first object, then the objects are said to be