66. Penetration test on bitumen is used to determine its:
ব্যাখ্যাঃ Bitumen penetration test is a basic test for determining the grades of bitumen. Penetration test is used for evaluating consistency of bitumen.
ব্যাখ্যা: The chief chemical components of portland cement are calcium or lime and silica. The percentage of lime and silica are 63% and 22%. Lime is derived from lime stone and silica comes from the sands and clay.
70. The arrangement made to support an unsafe structure temporarily as:
ব্যাখ্যা: Shoring is the process of temporarily supporting a building, structure or trench with shores when in danger of during repairs. Shoring comes from shore, a timber or metal. Shoring may be vertical angled or horizontal.
ব্যাখ্যা: Dead load comprise of permanently attached loads. Dead loads are the loads that will go no where in the structure and they are most important when designing slabs and beams. Dead load consists of own weight of the element and the weight of the floor finishing
77. Which one of the following is used for preparing porcelain?
ব্যাখ্যাঃ The principal clays used to make porcelain are chain a clay and ball clay. Feldspar a mineral comprsing mostly aluminium silicate, a type of hard quartz in the porcelain mixture.
78. A pipe conveying sewage from plumbing system of a single building to common sewer is called:
ব্যাখ্যা : Main sewer as the primary pipeline in a sewerage system to which all the branching pipes carrying sewage from different location. Submain sewer means a city or privated owned sewer pipe designed to convey sewage from two or more building laterals to a main sewer.