CBSE 11TH MATHEMATICS - Online Test

Q1. The mean of the first n terms of the A.P. (a + d ) + ( a + 3d ) + ( a + 5d ) +………..is
Answer : Option B
Explaination / Solution:



Q2. The line x + y – 6 = 0 is the right bisector of the segment [PQ]. If P is the point ( 4, 3 ) , then the point Q is
Answer : Option B
Explaination / Solution:

Equation of the line which is perpendicular to the given line x + y = 6 is x - y + k = 0

Since it passes through the point (4,3)

4 - 3 + k = 0

Therefore k = -1

Hence the equation of the line segment PQ is x - y - 1 = 0

On solving these two lines we get x = 7/2 and y = 5/2

This point of intersection is the midpoint of the line segement PQ

That is  = 7/2 Hence x = 3

Similarly  = 5/2. Hence y = 2

Hence the coordiates of the point Q is (3,2)


Q3. Negation of the statement (p∧r)→(r∨q) is
Answer : Option A
Explaination / Solution:

(p∧r)∧(∼r∧∼q) since ∼(p→q)≡p∧∼q

Q4. The equation of the normal to the parabola  having slope 1 is
Answer : Option C
Explaination / Solution:

slope form of normal is y=mx-2am-am3

for the given parabola a = 2 and m = 1

therefore y = x -4 -2 

i.e; x - y - 6 = 0


Q5. Let the angles A, B, C of ΔABC be in A.P. and let b: c:: , then the angle A is
Answer : Option D
Explaination / Solution:



Q6. The smallest positive integer ‘ n ‘ for which P ( n ) : holds is :
Answer : Option D
Explaination / Solution:

Since the values of n as 1,2,3gives inavlid inequations but when n = 4 we have 16<24, which is valid.

Q7. Two dice are thrown. The number of sample points in the sample space when 6 does not appear on either dice is
Answer : Option C
Explaination / Solution:

total no. of outcomes=62=36

The pair which shows 6 on either dice are {(6,1),(6,2),(6,3),(6,4),(6,5),(1,6),(2,6),(3,6),(4,6),(5,6),(6,6)}=11

So total number of sample points in sample space when 6 on either dice do not appear=36-11=25


Q8. The equation   represents
Answer : Option C
Explaination / Solution:

The equation  represents the plane z=0 as the equation can be written as 
In this z-coordinate is zero .So ,  this  represent XY plane i.e.  the plane Z=0

Q9. The number of even numbers that can be formed by using all the digits 1, 2, 3, 4, and 5 (without repetitions) is
Answer : Option C
Explaination / Solution:

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12342

Since we need an even number , ones place can be occupied by only two numbers 2 and 4 in two ways.

Since repetition is not allowed tens place is occupied by remaining 4 numbers in 4 ways and the hundred's place by 3 ways and thousands place in 2 ways.

Hence total number of even numbers can be formed in 1x2x3x4x2 = 48.


Q10. If the cube roots of unity are 1,  then roots of the equation  are :
Answer : Option B
Explaination / Solution: