Correct Answer: B. water
Solution:
Plastic paints, such as emulsion paints, are water-based. This means that water is used as the solvent or "thinner" to adjust the paint's consistency for application. Oil, naptha, and spirit are used for oil-based paints and varnishes.
Correct Answer: B. priming coat
Solution:
In a standard three-coat paint system, the very first layer applied to the bare surface is the priming coat or primer. Its purpose is to seal the surface and provide a uniform base for the subsequent coats to adhere to properly.
Correct Answer: B. pigment volume concentration
Solution:
Extenders, or fillers, are solid particles added to paint to increase its volume and reduce cost. Since they are part of the solid volume (like pigments), they increase the overall volume of pigment and filler relative to the binder. This directly increases the Pigment Volume Concentration (PVC), which can affect properties like gloss, permeability, and scrub resistance.
Correct Answer: D. Tung oil
Solution:
The vehicle in paint is the liquid component that carries the pigments and binder. It consists of the binder and the solvent/thinner. Tung oil is a drying oil that acts as a binder, which is a key part of the vehicle. Red lead and white lead are pigments/bases, and turpentine oil is a solvent/thinner.
Correct Answer: C. Pigment Value Concentration Number
Solution:
In paint science, the ratio of solid particles (pigments and fillers) to the liquid binder is a crucial factor. The most common term for this is PVC (Pigment Volume Concentration). The term PVCN is a less common variant that refers to the same fundamental concept, making "Pigment Value Concentration Number" the most logical answer among the choices.
Note: The source material indicates that this question was considered faulty by the official commission in the revised answer key. This is likely because PVCN is not a standard industry term, with PVC being the correct and universally accepted acronym. However, based on the options provided, this is the only plausible answer.
Correct Answer: C. Interior surface which are not exposed to environment
Solution:
Distempers are a type of water-based paint that are not very durable or resistant to moisture. Because of their low washability and susceptibility to weather, they are suitable only for interior surfaces that are not exposed to the elements, such as indoor walls and ceilings.
Correct Answer: D. French polish
Solution:
French polish is a traditional finishing technique that involves applying many thin coats of shellac. This process builds up a thick, high-gloss film that is excellent at filling the pores of the wood and masking minor grain defects, resulting in a very smooth and deep finish.
Correct Answer: C. vehicle
Solution:
The vehicle is the liquid portion of the paint that acts as a carrier for the solid components (base and pigment). It is typically an oil (like linseed oil) or water, and it allows the paint to be spread onto a surface.
Correct Answer: B. Linseed oil
Solution:
The terms "carrier" and "vehicle" are often used interchangeably in the context of paints. Linseed oil is a drying oil, meaning it hardens to a solid film when exposed to air. This property makes it an ideal carrier or vehicle for holding the pigment and forming the paint film.
Correct Answer: A. Linseed oil
Solution:
Enamel paints are typically oil-based. The vehicle for these paints consists of a drying oil (binder) and a solvent. While varnish is a key component that provides the hard, glossy finish, the fundamental binder and oil component is often linseed oil. Varnish itself is a mixture, not a single vehicle. Water is used for latex/emulsion paints.
Correct Answer: C. pigments
Solution:
Pigments are finely ground solid particles that perform two main functions in paint: they provide color and opacity (the ability to hide the surface underneath). This hiding power helps to cover minor surface imperfections.
Correct Answer: C. Flaking
Solution:
Flaking is a paint failure where pieces of the paint film lift and detach from the underlying surface. This is often caused by a loss of adhesion, which can result from poor surface preparation or moisture getting behind the paint film.
Correct Answer: D. Varnish
Solution:
A varnish, specifically a spirit varnish like shellac, is created by dissolving a resin in a solvent. When the solvent is alcohol, it forms a homogeneous (uniform) solution. The other options are paints, which are suspensions of pigments and other solids, not homogeneous solutions.
Correct Answer: C. asbestos paints
Solution:
Asbestos paints are formulated with asbestos, a fibrous silicate mineral known for its excellent fire-resistant properties. This makes the paint highly resistant to catching fire and spreading flames. (Note: Due to health risks, asbestos is now heavily regulated or banned in many applications).
Correct Answer: D. Chalk
Solution:
The primary base material, or body, for traditional distemper is chalk (calcium carbonate). This is mixed with water and a binder like glue size to create the paint.