Mathematics - Online Test

Q1. Magnitude of the vector  is
Answer : Option B
Explaination / Solution:



Q2. In a quadratic function, the value of the product of the roots (α, β) is 4. Find the value of 
Answer : Option A
Explaination / Solution:



Q3. If , then the value of is
Answer : Option A
Explaination / Solution:



Q4. A circle with its centre on the line y = x + 1 is drawn to pass through the origin and touch the line y = x + 2. The centre of the circle is
Answer : Option D
Explaination / Solution:

  be the equation of circle with (h,k) as the center and r be the radius.
As the center lies on the line y=x+1

=> k=h+1 or k=1+h --(i)

Circle passes through origin so (0,0) will satisfy the equatio of line so putting (0,0) in equation of circle we get 


putting k from (i) into (ii), we get


and as the circle touches the line y=x+2 so radius should be equal to the distance from the center to this line.


putting value ok k from (i) in above equation, we get


putting the value of r in (iii)


h= putting h in (i) we get k=

hence center is (



Q5. Let f and g be differentiable functions such that fog = I, the identity function. If g’ (a) = 2 and g (a) = b, then f ‘ (b) =
Answer : Option C
Explaination / Solution:



Q6.

If A =  then for all real values of θ


Answer : Option B
Explaination / Solution:



Q7. A student was asked to prove a statement P ( n ) by method of induction . He proved P ( k + 1 ) is true whenever P ( k ) Is true for all k ≥ 5 , k∈N and P ( 5 ) is true . On the basis of this he could conclude that P ( n ) is true
Answer : Option D
Explaination / Solution:

Yes because if it is true for n = k then it is true for all n ,which is the basic concept of mathematical induction.

Q8. A dice is rolled 6 times. The probability of obtaining 2 and 4 exactly three times each is
Answer : Option D
Explaination / Solution:

Total ways of getting 2 and 4 exactly 3 times is 6! / (3! 3!) = 20

Total number of ways in throwing 6 dice is 66

Therefore probability is 20/ 66 = 5/11664


Q9. The point equidistant from the points ( 0 , 0 , 0 ) , ( 1 , 0 , 0 ) , ( 0 , 2 , 0 ) , and ( 0 , 0 , 3 ) is
Answer : Option B
Explaination / Solution:

let the point equidistant from the points ( 0 , 0 , 0 ) , ( 1 , 0 , 0 ) , ( 0 , 2 , 0 ) , and ( 0 , 0 , 3 ) is (x ,y ,z)

then according to the given condition and  distance formula between two points we have


taking ist two expressions and solving them we get 


Similarly by taking ist and 3rd we get y = 1 and by taking ist and 4th we get z = 3/2

So the required point is ( 1/2 , 1 , 3/2 )


Q10.
Answer : Option A
Explaination / Solution: