CBSE 11TH MATHEMATICS - Online Test

Q1. If A = { 1,2,3,4 } and B = { 4,5,6,7 } then A−B =
Answer : Option C
Explaination / Solution:

Given A={1,2,3,4} and B={4,5,6,7}

A-B set will contain those elements which are present in A but not in B

we can see 

Now 

so 


Q2. Solve : 30x < 200, when x is a natural number :
Answer : Option C
Explaination / Solution:



Q3. If k be an integer, then  is equal to
Answer : Option A
Explaination / Solution:



Q4. If a∈R, then the roots of the equation tan x = a are in G.P for what values of a
Answer : Option C
Explaination / Solution:



Q5. If the mean of numbers 27,31,89,107,156 is 82 , then the mean of 130,126,68,50,1 is :
Answer : Option B
Explaination / Solution:

mean=130+126+68+50+15=3755=75
Q6. Two points ( a , 0 ) and ( 0 , b ) are joined by a straight line. Another point on this line is
Answer : Option A
Explaination / Solution:

The slope of the line joining the points (a,0) and (0,b) is [b-0]/[0-a] = -(b/a)

Hence the equation of the line is y = (-b/a)x +b

i.e; ay = -bx +ab

Substituting the x coordinate 3a in the place of x in the above equation we get y = -2b

Hence (3a,-2b) is another point on the line.


Q7. (p∧∼q)∧(∼p∨q) is
Answer : Option D
Explaination / Solution:

     Since 

F V F = F     Since       

Hence contracdiction

 


Q8. S and T are the foci of an ellipse and B is an end of the minor axis. If STB is an equilateral triangle, the eccentricity of the ellipse is
Answer : Option B
Explaination / Solution:

s = (ae,0) and T = (-ae,0) and B = (0,b)

Since it is an equilateral triangle, ST2 = TB2

This implies 4a2e2 = a2e2 + b2

3a2e2 = b

3a2e2 = a2(1 - e2)

3e2  = 1 - e2

Therefore e = 1/2


Q9. The smallest positive integer n , for which  holds :
Answer : Option C
Explaination / Solution:

When n = 1 we get ,which is invalid. When n = 2 we get, which is valid.

Q10. If sin  = 2, then 
Answer : Option D
Explaination / Solution: