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Ex 10.2, 18 (MCQ) - Chapter 10 Class 12 Vector Algebra
Last updated at Dec. 16, 2024 by Teachoo
Addition(resultant) of vectors
Chapter 10 Class 12 Vector Algebra
Concept wise
- Scalar or vector
- Graphical displacement
- Type of vector
- Multiplication of a vector by a scalar
- Equal vectors
- Unit vector
- Direction cosines and ratios
-
Addition(resultant) of vectors
- Joining two points
- Section formula
- Right Angled triangle
- Collinearity Of two vectors
- Collinearity of 3 points or 3 position vectors
- Scalar product - Defination
- Scalar product - Projection
- Scalar product - Solving
- Vector product - Defination
- Vector product - Area
- Vector product - Solving
Transcript
Ex 10.2, 18 In triangle ABC (Fig 10.18),which of the following is not true (A) (π΄π΅) β + (π΅πΆ) β + (πΆπ΄) β= 0 β (B) (π΄π΅) β + (π΅πΆ) β β (π΄πΆ) β= 0 β (C) (π΄π΅) β + (π΅πΆ) β β (πΆπ΄) β= 0 β (D) (π΄π΅) β β (πΆπ΅) β + (πΆπ΄) β= 0 β In Ξ ABC, (π΄πΆ) β is the resultant of (π΄π΅) β & (π΅πΆ) β (π΄πΆ) β = (π΄π΅) β + (π΅πΆ) β (π΄π΅) β + (π΅πΆ) β = (π΄πΆ) β (π΄π΅) β + (π΅πΆ) β β (π΄πΆ) β = 0 β Checking part (A) (π¨π©) β + (π©πͺ) β + (πͺπ¨) β= π β From (1) (π΄π΅) β + (π΅πΆ) β β (π΄πΆ) β = 0 β (π΄π΅) β + (π΅πΆ) β β (β(πΆπ΄) β) = 0 β (π΄π΅) β + (π΅πΆ) β + (πΆπ΄) β = 0 β Hence, (A) is true. Checking part (B) (π¨π©) β + (π©πͺ) β β (π¨πͺ) β= π β From (1) (π΄π΅) β + (π΅πΆ) β β (π΄πΆ) β = 0 β Hence, (B) is true. Checking part (C) (π¨π©) β + (π©πͺ) β β (πͺπ¨) β= π β From (1) (π΄π΅) β + (π΅πΆ) β β (π΄πΆ) β = 0 β (π΄π΅) β + (π΅πΆ) β β (β(πΆπ΄) β) = 0 β (π΄π΅) β + (π΅πΆ) β + (πΆπ΄) β = 0 β Hence, (C) is not true. Checking part (D) (π¨π©) β β (πͺπ©) β + (πͺπ¨) β= π β From (1) (π΄π΅) β + (π΅πΆ) β β (π΄πΆ) β = 0 β (AB) β β (CB) β + (CA) β = 0 β Hence, (D) is true. Thus, (C) is the correct option
