Question 609Steam Plants - Assistant Engineer

The correct answer is D) Water, agitation, and heat. The formation of an oil and water emulsion is caused by the presence of water, agitation, and heat. These factors allow the water to be dispersed into the oil, creating a stable emulsion. Aeration and solid insoluble particles can contribute to emulsion formation as well, but they are not the primary factors. The other options are incorrect because: A) Aeration and agitation can contribute to emulsion formation, but heat is the key factor in this process. B) Solid insoluble particles can contribute to emulsion formation, but they are not the primary driver. C) Water and solid insoluble particles alone are not sufficient to form an oil and water emulsion.