Building Materials Questions & Answers - Page 10

46.

Pick up the correct statement from the following

A.

For thin structures subjected to wetting and drying, the water cement ratio should be 0.45

B.

For mass concrete structures subjected to wetting and drying, the water ratio should be 0.55

C.

For thin structures which remain continuously under water, the water-cement ratio by weight should be 0.55

D.

For massive concrete structures which remain continuously under water, the water cement ratio by weight should be 0.65

E.

All the above

Correct answer is E

No explanation has been provided for this answer.

47.

Pick up the polymineralic rock from the following

A.

Quartz sand

B.

Pure gypsum

C.

Magnesite

D.

Granite

E.

None of these

Correct answer is D

Granite is a polymineralic rock, which means it is composed of a mixture of minerals. Granite is typically made up of quartz, feldspar, and mica, as well as smaller amounts of other minerals. The different minerals in granite give it a variety of colors and patterns, ranging from white to pink to black.

48.

Wrought iron contains carbon upto

A.

0.25%

B.

1.0%

C.

1.5%

D.

2%

Correct answer is A

No explanation has been provided for this answer.

49.

Lacquer paints

A.

are generally applied on structural steel

B.

are less durable as compared to enamel paints

C.

consist of resin and nitro-cellulose

D.

contain alcohol as thinner

E.

all the above.

Correct answer is E

Lacquer paints are generally applied on structural steel, are less durable as compared to enamel paints, consist of resin and nitro-cellulose, and contain alcohol as thinner. Lacquer paints are known for their fast-drying properties, high gloss finish, and ability to be applied in thin layers. They are often used on wood, metal, and other surfaces to provide a decorative finish. However, they are less durable than enamel paints, which are more resistant to wear and tear and tend to last longer. Lacquer paints consist of a resin (such as nitrocellulose, acrylic, or polyurethane) suspended in a solvent (such as alcohol or acetone). The solvent helps the paint flow smoothly and evaporates quickly, leaving behind the resin to form a hard and glossy finish.

50.

In a mortar, the binding material is

A.

cement

B.

sand

C.

surkhi

D.

cinder

Correct answer is A

A mortar is a mixture of binding material, water, and fine aggregate (such as sand or surkhi). The binding material is typically cement, which is a powder made of a mixture of calcined limestone and clay. When mixed with water, cement forms a paste that hardens over time to bind the aggregate together and create a strong and durable building material. Sand and surkhi are both types of fine aggregate that are often used in mortars, and cinder is a type of coarse aggregate that is not typically used in mortars.