RankLab
Back to Questions
MathsMediumMCQ2016 · 03 Apr

Q88.If the line, x−3 2 = y+2−1 = z+43 lies in the plane lx + my −z = 9, then l2 + m2 is equal to (1) 5 (2) 2 (3) 26 (4) 18

What This Question Tests

This question tests the conditions for a line to lie completely within a plane: a point on the line must satisfy the plane equation, and the direction vector of the line must be orthogonal to the normal vector of the plane.

Concepts Tested

Equation of a line in 3DEquation of a planeCondition for a line to lie in a planeDot product for perpendicularity

Formulas Used

Line: (x-x₁)/a = (y-y₁)/b = (z-z₁)/c

Plane: Ax+By+Cz=D

Condition for line in plane: A(x₁) + B(y₁) + C(z₁) = D and Aa+Bb+Cc=0

📚 NCERT Sections This Tests

2.1Two Charges 5 × 10–8 C And –3 × 10–8 C Are Located 16 Cm Apart. At

Physics Class 11 · Chapter 2

71% match

2.1 Two charges 5 × 10–8 C and –3 × 10–8 C are located 16 cm apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.

1.18A Point Charge Of 2.0 Mc Is At The Centre Of A Cubic Gaussian

Physics Class 11 · Chapter 1

71% match

1.18 A point charge of 2.0 mC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?

4.4A Horizontal Overhead Power Line Carries A Current Of 90 A In East To

Physics Class 11 · Chapter 4

70% match

4.4 A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current 1.5 m below the line?