Properties of Lubrication – 2

·         ____________ is the property which enables oil to spread over and adhere to the surface of the bearing.

Answer: Oiliness is the property which enables oil to spread over and adhere to the surface of the bearing and pour point is the lowest temperature at which the lubricating oil will pour while fire point is the lowest temperature at which the oil burns continuously.

·         A lubricant should not corrode the working parts and it must retain its properties even in the presence of foreign matter and additives.

Answer: True

·         A lubricating oil, when mixed with water is emulsified and loses its lubricating property.

Answer: True

·         The emulsification number is an index of the tendency of an oil to emulsify with water.

Answer: True

·         A lubricating oil need not be stable physically at the lowest and highest temperatures between which the oil is to be used.

Answer: Actually, a lubricating oil must be stable physically at the lowest and highest temperatures between which the oil is to be used.

·         At the lowest temperature there should separation of solids, and at the highest temperature it should not vapourise beyond a certain limit.

Answer: No, at the lowest temperature there should not be any separation of solids, and at the highest temperature it should not vapourise beyond a certain limit.

·         ____________ is the property of lubricating oil due to which the oil particles stick with the metal surfaces.

Answer: Adhesiveness is the property of lubricating oil due to which the oil particles stick with the metal surfaces while oiliness is the property which enables oil to spread over and adhere to the surface of the bearing.

·         ____________ is the property of a lubricating oil due to which the oil retains a thin film between the two surfaces.

Answer: Film Strength is the property of a lubricating oil due to which the oil retains a thin film between the two surfaces and adhesiveness is the property of lubricating oil due to which the oil particles stick with the metal surfaces while oiliness is the property which enables oil to spread over and adhere to the surface of the bearing.

·         ____________ is the measure of density of oil.

Answer: Specific gravity is the measure of density of oil while film Strength is the property of a lubricating oil due to which the oil retains a thin film between the two surfaces and adhesiveness is the property of lubricating oil due to which the oil particles stick with the metal surfaces.

·         The sludge formation takes place as a result of operation at low engine temperatures during starting, warming up, and idling periods.

Answer: True

·         A high viscosity index is always desired for lubricating oils as it can be used in severe winter and summer conditions.

Answer: False