Mathmatics NDA/NA Solved Paper 2020-I (100-120)

Total Questions: 20

1. If f(๐“) = 2๐“ - ๐“ยฒ, then what is value of f(๐“ + 2) + f(๐“ - 2) when ๐“ = 0 ?

Correct Answer: (a) - 8
Solution:

2. If ๐“แตyโฟ = aแตโบโฟ then what is dy/d๐“ equal to?

Correct Answer: (b)
Solution:

3. Solve the following equation?

Correct Answer: (a)
Solution:


4. What is the minimum value of |x - 1|, where x โˆˆ R?

Correct Answer: (a) 0
Solution:

Minimum value of any modulus is 0.

5. What is the value of k such that integration of 3๐“ยฒ + 8 + 4k/๐“ with respect to ๐“, may be a rational function?

Correct Answer: (c) 2
Solution:

6. What is the length of the diameter of the sphere whose centre is at (1, -2, 3) and which touches the plane 6x - 3y + 2z - 4 = 0 ?

Correct Answer: (d) 4 units
Solution:

7. What is the perpendicular distance from the point (2, 3, 4) to the line

Correct Answer: (b) 5 units
Solution:

8. If a line has direction ratios <a>, then what is the sum of the squares of its direction cosines ?

Correct Answer: (d) 1
Solution:

9. Into how many compartments do the coordinate planes divide the space ?

Correct Answer: (c) 8
Solution:


Co-ordinate plane divide the space into 8 octanes.

10. What is the equation of the plane which cuts an intercept 5 units on the z-axis and it parallel to ๐“y-plane ?

Correct Answer: (b) z = 5
Solution:

Equation of the plane which cuts an intercept 5 units on the z-axis and is parallel to ๐“y-plane, is z = 5, y = 0, ๐“ = 0.