Three Dimensional Geometry - Online Test

Q1. Find the equation of the line in cartesian form that passes through the point (– 2, 4, – 5) and parallel to the line given by
Answer : Option D
Explaination / Solution:

Find the equation of the line in cartesian form that passes through the point (– 2, 4, – 5) and parallel to the line given by
 
is given by:
 And l = 3 , m = 5 and n = 6 .
Therefore , 
.

Q2. Find the cartesian equations of the lines that passes through the origin and (5, – 2, 3).
Answer : Option C
Explaination / Solution:

The coordinates of the origin are ( 0 , 0 ,0 ) , therefore , , and l = 5 , m = - 2 and n = 3 , 
therefore the equation in Cartesian form is given by:

i.e. .

Q3. Find the vector equations of the line that passes through the points (3, – 2, – 5), (3, – 2, 6).
Answer : Option C
Explaination / Solution:

Here ,  and 
Therefore , the vector equation is :
 
i.e..

Q4.
Find the values of p so that the linesare at right angles.

Answer : Option B
Explaination / Solution:



Q5. Find the shortest distance between the lines  
Answer : Option D
Explaination / Solution:



Q6. Find the shortest distance between the lines 
Answer : Option C
Explaination / Solution:





Q7. Find the shortest distance between the lines : 
Answer : Option D
Explaination / Solution:

On comparing the given equations with:
, we get: 


Q8. Find the shortest distance between the lines 
Answer : Option C
Explaination / Solution:

The given equations can be reduced as: 


Q9. In the vector form, equation of a plane which is at a distance d from the origin, and  is the unit vector normal to the plane through the origin is
Answer : Option D
Explaination / Solution:

In the vector form, equation of a plane which is at a distance d from the origin, and  is the unit vector normal to the plane through the origin is given by : 

Q10. Equation of a plane which is at a distance d from the origin and the direction cosines of the normal to the plane are l, m, n is.
Answer : Option D
Explaination / Solution:

In Cartesian co – ordinate system Equation of a plane which is at a distance d from the origin and the direction cosines of the normal to the plane are l, m, n is given by : lx + my + nz = d.