If the direction ratio of two lines are given by l + m + n = 0, m

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

731.

XOZ-plane divides the join of (2, 3, 1) and(6, 7, 1) in the ratio :

  • 3 : 7

  • 2 : 7

  • - 3 : 7

  • - 2 : 7


732.

If the direction ratio of two lines are given by 3lm - 4ln + mn = 0 and l + 2m + 3n = 0, then the angle between the lines, is :

  • π6

  • π4

  • π3

  • π2


733.

A plane makes intercepts 3 and 4 respectively on Z-axis and X-axis. If it is parallel to Y-axis, then its equation is

  • 3x + 4z = 12

  • 3z + 4x = 12

  • 3y + 4z = 12

  • 3z + 4y = 12


734.

The equation of the plane passing through(1, 1, 1) and   (1, - 1, - 1) and perpendicular to 2x -y + z = 0 is :

  • 2x +5y +z + 8 = 0

  • x + y - z - 1 = 0

  • 2x + 5y + z + 4 = 0

  • x - y + z - 1 = 0


Advertisement
735.

If 3i^ + 3j^ + 3k^, 3i^ + 3j^ + λk^ are coplaner, then λ is equal to

  • 1

  • 2

  • 3

  • 4


Advertisement

736.

If the direction ratio of two lines are given by l + m + n = 0, mn - 2ln + lm = 0, then the angle between the lines is

  • π4

  • π3

  • π2

  • 0


C.

π2

Given lines are l + m + n = 0  ... iand mn - 2ln + lm = 0   ... iiFrom equation il = - m + nPutting inequation ii, we get      mn + 2m + nn - m + nm = 0 mn + 2mn + 2n2 - m2 - nm = 0                        2n2 - m2 + 2nm = 0 2nm2 + 2nm - 1 = 0This is a quadratic equation in nm. n1n2m1m2 = - 12  ....iiiwhere n1m1, n2m2 are the roots of equationFrom equation im = - n + lPutting equation ii, we get- n + ln - 2ln - ln + ln2 + ln + 2ln  + ln + l2 = 0

     l2 + 3ln + n2 = 0 ln2 + 3ln + 1 = 0                  l1l2n1n2 = 1     ...ivWhere l1n1, l2n2 are the roots of the equationFrom equations iii and iv, we get                 l1l2 = - 12m1m2  = n1n2    l1l21 = m1m2- 2 = n1n21 = 1    sayNow,  l1l2 + m1m2 + n1n2                       = 1 - 2 + 1 = 0               cosθ = 0  θ = 90°


Advertisement
737.

If (2, - 1, 3) is the foot of the perpendicular drawn from the origin to the plane, then the equation of the plane is

  • 2x + y - 3z + 6 = 0

  • 2x - y + 3z - 14 = 0

  • 2x - y + 3z - 13 = 0

  • 2x + y + 3z - 10 = 0


738.

If the plane 3x - 2y - z - 18 = 0 meets the coordinate axes in A, B, C then the centroid of ABC is

  • (2, 3, - 6)

  • (2, - 3, 6)

  • (- 2, - 3, 6)

  • (2, - 3, - 6)


Advertisement
739.

The direction cosines of the line passing through P(2, 3, - 1) and the origin are

  • 214, 314, 114

  • 214, - 314, 114

  • - 214, - 314, 114

  •  214, - 314, - 114


740.

If the direction cosines of two lines are such that l + m + n = 0, l2 + m2 - n2 = 0, then the angle between them is :

  • π

  • π3

  • π4

  • π6


Advertisement