1. What is the full form of rH?
a) Rhesus factor
b) Relative humidity
c) Rush hour
d) Radio head
Explanation: Relative Humidity (RH) is the ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature.
2. Water cement ratio is ______
a) Volume of water to the volume of cement
b) Volume of water to the volume of concrete
c) Volume of concrete to the volume of cement
d) Volume of water to the volume of aggregates
Explanation: The water–cement ratio is the ratio of the weight of water to the weight of cement used in a concrete mix.
3. A lower ratio leads to _____
a) High strength
b) Low strength
c) Low durability
d) Ease to work
Explanation: A lower ratio leads to higher strength and durability, but may make the mix difficult to work with and form.
4. For concrete exposed to a very aggressive environment the w/c should be lower than _________
a) 1
b) .5
c) .4
d) .8
Explanation: Higher is the aggressiveness of the environment lower should be the w/c ratio. For concrete exposed to a very aggressive environment, the w/c should be lower than 0.40.
5. What is the range of water in M10?
a) 34-36L
b) 29-32L
c) 26-30L
d) 21-27L
Explanation: The range of water for M10 (1:3:6) is 34 to 36 liters with a weight of 226kg of cement.
6. What is the range of water in M15?
a) 34-36L
b) 29-32L
c) 26-30L
d) 21-27L
Explanation: The range of water for M15 (1:2:4) is 29 to 32 liters with a weight of 313kg of cement.
7. What is the range of water in M20?
a) 34-36L
b) 29-32L
c) 26-30L
d) 21-27L
Explanation: The range of water for M20 (1:1.5:3) is 26 to 30 liters with a weight of 404kg of cement.
8. What is the range of water in M25?
a) 34-36L
b) 29-32L
c) 26-30L
d) 21-27L
Explanation: The range of water for M25 (1:1:2) is 21 to 27 liters with a weight of 563 kg of cement.
9. What is the approximate quantity of water in M5?
a) 60L
b) 45L
c) 34L
d) 85L
Explanation: The approximate quantity of water in grade M5 is nearly equal to 60 liters.
10. What is the approximate quantity of water in M7?
a) 60L
b) 45L
c) 34L
d) 85L
Explanation: The approximate quantity of water in grade M7 is nearly equal to 45 liters.