Q89.The angle between the lines whose direction cosines satisfy the equations l + m + n = 0 and l2 = m2 + n2 is (1) π (2) π 6 2 (3) π (4) π 3 4 = 14 , where A stands for¯¯¯
What This Question Tests
This question requires solving a system of two equations to find the direction cosines of two lines and then using the dot product formula to determine the angle between them.
Concepts Tested
Formulas Used
cos θ = |l₁l₂ + m₁m₂ + n₁n₂|
l²+m²+n²=1
📚 NCERT Sections This Tests
1.14 — Consider A Uniform Electric Field E = 3 × 103 Î N/C. (A) What Is The
Physics Class 11 · Chapter 1
1.14 Consider a uniform electric field E = 3 × 103 î N/C. (a) What is the flux of this field through a square of 10 cm on a side whose plane is parallel to the yz plane? (b) What is the flux through the same square if the normal to its plane makes a 60° angle with the x-axis?
2.3 — Two Charges 2 Mc And –2 Mc Are Placed At Points A And B 6 Cm
Physics Class 11 · Chapter 2
2.3 Two charges 2 mC and –2 mC are placed at points A and B 6 cm apart. (a) Identify an equipotential surface of the system. (b) What is the direction of the electric field at every point on this surface?
2.1 — Two Charges 5 × 10–8 C And –3 × 10–8 C Are Located 16 Cm Apart. At
Physics Class 11 · Chapter 2
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.
📋 Question Details
- Chapter
- 3D Geometry
- Topic
- Angle between two lines
- Year
- 2014
- Shift
- 06 Apr
- Q Number
- Q89
- Type
- MCQ
- NCERT Ref
- Class 12 Mathematics Ch 11: Three Dimensional Geometry
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