Civil Engineering - Online Test

Q1. Consider the matrix as given below.

Which one of the following provides the CORRECT values of eigenvalues of the matrix? 
Answer : Option A
Explaination / Solution:

Given matrix is upper triangular matrix and its diagonal elements are its eigen values = 1, 4, 3

Q2. An application loads 100 libraries at startup. Loading each library requires exactly one disk access. The seek time of the disk to a random location is given as 10ms. Rotational speed of disk is 6000rpm. If all 100 libraries are loaded from random locations on the disk, how long does it take to load all libraries? (The time to transfer data from the disk block once the head has been positioned at the start of the block may be neglected)
Answer : Option B
Explaination / Solution:

6000 rotations ________ 60 sec 1 rotation ________10 ms Rotational latency = 5ms Time for one disk access = 15 ms Time to load all libraries = 15 ×100 = 1500ms = 1.5 sec

Q3. Given i = −1, what will be the evaluation of the definite integral 
Answer : Option D
Explaination / Solution:



Q4. Consider a finite sequence of random values X = [x1x2,...xn]. Let µx be the mean and σx be the standard deviation of X .Let another finite sequence Y of equal length be derived from this as yi = a* xi + b, where a and b are positive constants. Let µy be the mean and σy be the standard deviation of this sequence. Which one of the following statements is INCORRECT? 
Answer : Option D
Explaination / Solution:
No Explaination.


Q5. A deck of 5 cards (each carrying a distinct number from 1 to 5) is shuffled thoroughly. Two cards are then removed one at a time from the deck. What is the probability that the two cards are selected with the number on the first card being one higher than the number on the second card?
Answer : Option A
Explaination / Solution:

(2,1), (3,2), (4,3), (5,4) Required probability = 4/(5×4) = 4/20 = 1/5

Q6. If Log (P) = (1/2)Log (Q) = (1/3) Log (R), then which of the following options is TRUE?
Answer : Option B
Explaination / Solution:



Q7. P, Q, R and S are four types of dangerous microbes recently found in a human habitat. The area of each circle with its diameter printed in brackets represents the growth of a single microbe surviving human immunity system within 24 hours of entering the body. The danger to human beings varies proportionately with the toxicity, potency and growth attributed to a microbe shown in the figure below 
A pharmaceutical company is contemplating the development of a vaccine against the most dangerous microbe. Which microbe should the company target in its first attempt? 

Answer : Option D
Explaination / Solution:

 By observation of the table, we can say S 


Q8. The variable cost (V) of manufacturing a product varies according to the equation V= 4q, where q is the quantity produced. The fixed cost (F) of production of same product reduces with q according to the equation F = 100/q. How many units should be produced to minimize the total cost (V+F)?
Answer : Option A
Explaination / Solution:

Checking with all options in formula: (4q+100/q) i.e. (V+F). Option A gives the minimum cost.

Q9. A container originally contains 10 litres of pure spirit. From this container 1 litre of spirit is replaced with 1 litre of water. Subsequently, 1 litre of the mixture is again replaced with 1 litre of water and this process is repeated one more time. How much spirit is now left in the container?
Answer : Option D
Explaination / Solution:



Q10. Consider a random variable X that takes values + 1 and -1 with probability 0.5 each. The values of the cumulative distribution function F(x) at x = -1 and +1 are
Answer : Option C
Explaination / Solution:

The cumulative distribution function F(x) = P(X ≤ x) F(-1) = P(X ≤ -1) = P(X = -1) = 0.5 F(+1) = P(X ≤ +1) = P(X = -1) + P(X = +1) = 0.5 + 0.5 = 1