1
The lines 2x = 3y = $$-$$ z and 6x = $$-$$ y = $$-$$ 4z
2
The radius of the sphere $$3{x^2} + 3{y^2} + 3{z^2} - 8x + 4y + 8z - 15 = 0$$ is
3
The direction ratios of the line perpendicular to the lines with direction ratios < 1, $$-$$2, $$-$$2 > and < 0, 2, 1 > are
4
What are the coordinates of the foot of the perpendicular drawn from the point (3, 5, 4) on the plane z = 0 ?
5
The lengths of the intercepts on the coordinate axes made by the plane 5x + 2y + z $$-$$ 13 = 0 are
6
Consider the following statements.
I. The coordinates of Q are (4, $$-$$3, $$-$$1).
II. PQ is the length more than 8 units.
III. The point (1, $$-$$1, $$-$$3) is the mid-point of the line segment PQ and lies on the given plane.
which of the above statements are correct?
7
Consider the following statements.
I. The direction ratios of the segment PQ are <3, $$-$$2, 2>
II. The sum of the squares of direction cosines of the line segment PQ is unity.
Which of the above statements is/are correct?
8
What are the direction ratios of the line of intersection of the given planes?
9
What is the equation of the line L ?
10
What are the direction ratios of the line of intersection of the given planes?
11
What is the equation of the plane P?
12
If the plane P touches the sphere $${x^2} + {y^2} + {z^2} = {r^2}$$, then what is r equal to?
13
The length of the normal from origin to the plane x + 2y $$-$$ 2z = 9 is equal to
14
If $$\alpha$$, $$\beta$$ and $$\gamma$$ are the angles which the vector OP (O being the origin) makes with positive direction of the coordinate axes, then which of the following are correct?
1. $${\cos ^2}\alpha + {\cos ^2}\beta = {\sin ^2}\gamma $$
2. $${\sin ^2}\alpha + {\sin ^2}\beta = {\cos ^2}\gamma $$
3. $${\sin ^2}\alpha + {\sin ^2}\beta + {\sin ^2}\gamma = 2$$
Select the correct answer using the code given below.
15
The point of intersection of the line joining the points ($$-$$3, 4, $$-$$8) and (5, $$-$$6, 4) with XY-plane is
16
If the angle between the lines whose direction ratios are (2, $$-$$1, 2) and is $${\pi \over 4}$$, then the smaller value of x is
17
A variable plane passes through a fixed point (a, b, c) and cuts the axes in A, B, and C respectively. The locus of the centre of the sphere OABC, O being the origin, is
18
The equation of the plane passing through the line of intersection of the planes x + y + z = 1, 2x + 3y + 4z = 7, and perpendicular to the plane x $$-$$ 5y + 3z = 5 is given by
19
A straight line with direction cosines <0, 1, 0> is
20
(0, 0, 0), (a, 0, 0), (0, b, 0) and (0, 0, c) are four distinct points. What are the coordinates of the point which is equidistant from the four points?
21
The points P(3, 2, 4), Q(4, 5, 2), R(5, 8, 0) and S(2, $$-$$1, 6) are
22
The line passing through the points (1, 2, $$-$$1) and (3, $$-$$1, 2) meets the yz-plane at which one of the following points?
23
Under which one of the following conditions are the lines x = ay + b; z = cy + d and x = ey + f; z = gy + h perpendicular?
24
What is the distance of the point (2, 3, 4) from the plane 3x $$-$$ 6y + 2z + 11 = 0 ?
25
Coordinates of the points O, P, Q and R respectively (0, 0, 0), (4, 6, 2m), (2, 0, 2n) and (2, 4, 6) L, M, N and K OR, OP, PQ and QR respectively such that LMNK is a parallelogram whose two adjacent sides LK and LM are each of length $$\sqrt 2 $$ ?
26
The line $${{x - 1} \over 2} = {{y - 2} \over 3} = {{z - 3} \over 4}$$ is given by
27
Consider the following statements
1. The angle between the planes 2x $$-$$ y + z = 1 and x + y + 2z = 3 is $${\pi \over 3}$$
2. The distance between the planes 6x $$-$$ 3y + 6z + 2 = 0 and 2x $$-$$ y + 2z + 4 = 0 is $${{10} \over 9}$$
Which of the above statement is/are correct?
28
Let the coordinates of the points A, B, C be (1, 8, 4), (0, $$-$$11, 4) and (2, $$-$$3, 1) respectively. What are the coordinates of the point D which is the foot of the perpendicular from A on BC ?
29
What is the equation of the plane passing through the points ($$-$$2, 6, $$-$$6), ($$-$$3, 10, $$-$$9) and ($$-$$5, 0, $$-$$6) ?
30
A sphere of constant radius r through the origin intersects the coordinate axes in A, B and C. What is the locus of the centroid of the $$\Delta$$ABC ?
31
The coordinates of the vertices P, Q and R of a triangle PQR are (1, $$-$$1, 1), (3, $$-$$2, 2) and (0, 2, 6) respectively. If $$\angle$$RQP = $$\theta$$, then what is $$\angle$$PRQ equal to?
32
If the line $${{x - 4} \over 1} = {{y - 2} \over 1} = {{z - k} \over 2}$$ lies on the plane $$2x - 4y + z = 7$$, then what is the value of k?
33
A point on the line $${{x - 1} \over 1} = {{y - 3} \over 2} = {{z + 2} \over 7}$$ has coordinates
34
If the points (x, y, $$-$$3), (2, 0, $$-$$1) and C (4, 2, 3) lie on a straight line, then what are the values of x and y respectively?
35
A straight line passes through the point (1, 1, 1) makes an angle 60$$^\circ$$ with the positive direction of Z-axis, and the cosine of the angles made by it with the positive directions of the Y-axis and the X-axis are in the ratio $$\sqrt 3 $$ : 1. What is the acute angle between the two possible positions of the line?
36
A point on a line has coordinates (p + 1, p $$-$$ 3, $$\sqrt 2 $$p) where p is any real number. What are the direction cosines of the line?
37
The centroid of the triangle with vertices A(2, $$-$$3, 3), B(5, $$-$$3, $$-$$4) and C(2, $$-$$3, $$-$$2) is the point
38
What is the radius of the sphere $${x^2} + {y^2} + {z^2} - 6x + 8y - 10z + 1 = 0$$ ?
39
The equation of the plane passing through the intersection of the planes 2x + y + 2z = 9, 4x $$-$$ 5y $$-$$ 4z = 1 and the point (3, 2, 1) is
40
The distance between the parallel planes $$4x - 2y + 4z + 9 = 0$$ and $$8x - 4y + 8z + 21 = 0$$
41
What are the direction cosines of Z-axis?
46
If L is the line with direction ratios < 3, -2, 6 > and passing through (1, -1, 1), then what are the coordinates of the points on L whose distance from (1, -1, 1) is 2 units?
NDA Mathematics 3 September 2023
47
Which one of the planes is parallel to the line $\rm \frac{x-2}{3}=\frac{y-3}{4}=\frac{z-4}{5}$ ?
NDA Mathematics 3 September 2023
48
What is the angle between the lines 2x = 3y = -z and 6x = -y = -4z?
NDA Mathematics 3 September 2023
49
What is the equation of the sphere concentric with the sphere x2 + y2 + z2 - 2x - 6y -8z - 5 = 0 and which passes through the origin?
NDA Mathematics 3 September 2023
50
A point P lies on the line joining A(1, 2, 3) and B(2, 10, 1). If z-coordinate of P is 7, what is the sum of other two coordinates?
NDA Mathematics 3 September 2023
51
What is u + v + w equal to ?
NDA Mathematics 16 April 2023
52
P(x, y, z) is any point on the sphere, then what is PA2 + PB2 equal to ?
NDA Mathematics 16 April 2023
54
What are the direction ratios of a line which is perpendicular to both the lines ?
NDA Mathematics 16 April 2023
57
A plane cuts intercepts 2, 2, 1 on the coordinate axes. What are the direction cosines of the normal to the plane?
NDA Mathematics 4 September 2022
60
If p is the perpendicular distance from the centre of the sphere to the plane, then which one of the following is correct ?
NDA Mathematics 10 April 2022
61
What is the equation of the line through the origin and the centre of the sphere ?
NDA Mathematics 10 April 2022
62
What are the direction ratios of the normal to the plane ?
NDA Mathematics 10 April 2022
63
If p, q and r are the intercepts made by the plane on the coordinate axes respectively, then what is (p + q + r) equal to ?
NDA Mathematics 10 April 2022
64
What is the angle between the two lines having direction ratios (6, 3, 6) and (3, 3, 0)?
NDA Mathematics 18 April 2021
65
If l, m, n are the direction cosines of the line x - 1 = 2(y + 3) = 1 - z, then what is l4 + m4 + n4 equal to?
NDA Mathematics 18 April 2021
66
What is the number of possible values of k for which the line joining the points (k, 1, 3) and (1, -2, k + 1) also passes through the point (15, 2, -4)?
NDA Mathematics 18 April 2021
67
The foot of the perpendicular drawn from the origin to the plane x + y + z = 3 is
NDA Mathematics 18 April 2021