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If the direction cosines of a line are ...

If the direction cosines of a line are k, k and k, then :

A

k `gt` 0

B

0 `lt ` k `lt` 1

C

k = 1

D

`k = (1)/(sqrt(3)) or - (1)/(sqrt(3))`.

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The correct Answer is:
D
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MODERN PUBLICATION-THREE DIMENSIONAL GEOMETRY -OBJECTIVE TYPE QUESTIONS (A. MULTIPLE CHOICE QUESTIONS)
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  2. The distance of the point P(a,b,c) from the x-axis is

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  3. If the direction cosines of a line are k, k and k, then :

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  4. reflection of the point (alpha, beta, gamma) in the XY-plane is :

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  5. What is the distance (in units) between the two planes 3x+5y+7z=3 " ...

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  6. the equation of the line in vector form passing through the point (-1,...

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  7. Direction-ratios of normal to plane which is parallel to the plane 3x ...

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  8. The relation between direction-cosines l, m and n of a line is :

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  9. The direction cosines of x-axis are (A) 0,0,1 (B) 1,0,0 (C) 0,1,0 (D) ...

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  10. What are the direction cosines of Z-axis?

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  11. If the line vec(r) = (-2 hati + 3 hatj + 4 hatk ) + lambda ( - hatk ha...

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  12. Distance between plane 3x + 4y - 20 = 0 and point (0,0,-7) is :

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  13. If a line makes an angle of pi/4 with each of Y and Z-axes , then the ...

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  14. If a line makes angles alpha,beta,gamma with the positive direction of...

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  15. If a line makes angles (pi)/(2), (3pi)/(4) and (pi)/(4) with x,y,z axi...

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  16. If direction-cosines of two lines are proportional to 4,3,2 and 1, -2,...

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  17. The direction consines of a line equally inclined with the co-ordinate...

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  18. The line (x-1)/2=(y-2)/4=(z-3)/4 meets the plane 2x+3y-z=14 in the poi...

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  19. Direction-ratios of line given by : (x -1)/(3) = (2y + 6)/(10) = (1...

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  20. Find the distance of the plane 3x\ \ 4y+12 z=3 from the origin.

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