21. If a two-lane National Highway and a two-lane State Highway intersect at right angles, the number of potential conflict points at the intersection, assuming that both the roads are two-way is ____. |
A. 11 |
B. 14 |
C. 24 |
D. 32 |
Answer: C 24 |
Explanation: On a right angled road intersection with two way traffic there are – 16 crossing conflicts which are the major conflict points, 4 merging and diverging conflicts which are the minor conflicts Hence, the total number of conflict points are 24. |
22. The penetration value of a bitumen sample tested at 25°C is 80. When this sample is heated to 60°C and tested again, the needle of the penetration test apparatus penetrates the bitumen sample by d mm. The value of d can’t be less than ___ mm. |
A. 5 |
B. 8 |
C. 10 |
D. 20 |
Answer: B 8 |
23. A combined value of flakiness and elongation index is to be determined for a sample of aggregates. The sequence in which the two tests are conducted is ____. |
A. elongation index test followed by flakiness index test on non-elongated aggregates |
B. elongation index test followed by flakiness index test on the whole sample |
C. flakiness index test followed by elongation index test on the whole sample |
D. flakiness index test followed by elongation index test on non-flaky aggregates |
Answer: D flakiness index test followed by elongation index test on non-flaky aggregates |
24. Aggregate impact value indicates ____ property of aggregates. |
A. Durability |
B. Hardness |
C. Strength |
D. Toughness |
Answer: D Toughness |
25. In Marshall testing of bituminous mixes, as the bitumen content increases the flow value _____. |
A. increases monotonically |
B. increases first and then decreases |
C. decreases first and then increases |
D. remains constant |
Answer: A increases monotonically |