Engineering Mathematics - Online Test

Q1. The following sequence of numbers is arranged in increasing order: 1, x, x, x, y, y,9,16,18. Given that the mean and median are equal, and are also equal to twice the mode, the value of y is
Answer : Option D
Explaination / Solution:

Given, Mean = Median = 2Mode
Mean = Median = 2x [Mode = x].............. (1)
Mean of the data = (3x + 2y + 44)/9
2x = (3x + 2y + 44)/9 
15x - 2y = 44.............(2)
Median of the data = y.........(3)
y = 2x ..........(4)
From (2); 11x = 44
x = 4
y = 8

Q2. If the radius of a right circular cone is increased by 50%, its volume increases by
Answer : Option C
Explaination / Solution:

Given, radius of a right circular cone is increased by 50%. 
Let, height of the circular cone=(h)


Q3. In a process, the number of cycles to failure decreases exponentially with an increase in load. At a load of 80 units, it takes 100 cycles for failure. When the load is halved, it takes 10000 cycles for failure. The load for which the failure will happen in 5000 cycles is __________.
Answer : Option B
Explaination / Solution:

From the data given we assume 
load = exp onent/log(cycles)
80 = x/log(10000)
x = 160
40 = x/log(10000)
x = 160
load = 160/log 5000 = 43.25

Q4. If f(x7) = 2x7 + 3x - 5, which of the following is a factor of f(x)?
Answer : Option B
Explaination / Solution:

from the option (b0 substitute x=1 in 
2x7 + 3x - 5 = 0
2(1)7 + 3(1) - 5 = 0 
5 - 5 = 0
So (x - 1) is a factor of f (x)

Q5. The type of partial differential equation 
Answer : Option C
Explaination / Solution:

Comparing the given equation with the general form of second order partial differential equation, we have A=1, B=3, C=1
B2- 4AC = 5 > 0
P.D.E is Hyperbola. 

Q6. If the entries in each column of a square matrix M add up to 1, then an eigen value of M is
Answer : Option D
Explaination / Solution:

Consider the '2x2 ' square matrix  Characteristic equation of M is
λ- (a + d)λ + (ad - bc) = 0......................(1)
Put λ =1, weget 
1 - (a + d) + ad - bc = 0 
1 - a - d + ad - (1 - d)(1 - a) = 0 
1 - a - d + ad - 1 + a + d - ad = 0 
0 = 0,which is true
λ = 1 Satisfies the equation (1) but λ = 2,3,4 does not satisfy the equation (1). For all possible values of a,d 


Q7. Type II error in hypothesis testing is
Answer : Option A
Explaination / Solution:

Type II Errors means acceptance of the null hypothesis when it is false and should be rejected.

Q8. The solution of the partial differential equation  is of the form
Answer : Option B
Explaination / Solution:



Q9. In shear design of an RC beam, other than the allowable shear strength of concrete (τc), there is also an additional check suggested in IS 456-2000 with respect to the maximum permissible shear stress (τc max). The check for τc max max is required to take care of
Answer : Option D
Explaination / Solution:
No Explaination.


Q10. Probability density function of a random variable X is given below

Answer : Option A
Explaination / Solution: