CBSE 12TH MATHEMATICS - Online Test

Q1. The area of bounded by the curve  and the coordinate axes is
Answer : Option B
Explaination / Solution:



Q2. Let R be the relation in the set {1, 2, 3, 4} given by R = {(1, 2), (2, 2), (1, 1), (4, 4), (1, 3), (3, 3), (3, 2)}. Then R is
Answer : Option D
Explaination / Solution:

The relation R is not symmetric , (1,2) ∈R , but (2,1) ∉ R , (1,3) ∈R ,but (3,1) ∉ R , (3,2) ∈R, but (2,3) ∉R.

Q3. A determinant is unaltered , if
Answer : Option C
Explaination / Solution:

This is because of the elementary transformations of determinants . The value of determinant remains unaffected by applying elementary transformations.

Q4.

 dx is equal to


Answer : Option C
Explaination / Solution:



Q5. The scalar product of the vector  with a unit vector along the sum of vectors  is equal to one. Find the value of.
Answer : Option A
Explaination / Solution:

Let  and 

Therefore, a unit vector along
 is given by:


Also, scalar product of  with above unit vector is 1.


Q6. Which of the following is different from ?
Answer : Option B
Explaination / Solution:


 

therefore , none of these is the right option.


Q7.  is equal to
Answer : Option D
Explaination / Solution:



Q8. If , then ,which of the following is true :
Answer : Option A
Explaination / Solution:

The given matrix is a skew – symmetric matrix.,therefore , A = - A’.

Q9. Find the equation of the plane through the line of intersection of the planes x + y + z = 1 and 2x + 3y + 4z = 5 which is perpendicular to the plane x – y + z = 0.
Answer : Option D
Explaination / Solution:

The equation of the plane through the line of intersection of the planes 


Q10. Forming a differential equation representing the given family of curves by eliminating arbitrary constants a and b from yields the differential equation
Answer : Option A
Explaination / Solution: