The multiplication of two vector quantities gives
The multiplication of two vector quantities gives Correct Answer either 1 or 2
Concept:
Vector Quantities
- A physical quantity that requires magnitude and a particular direction, when it is expressed
- Vector quantity must obey the rule of vector algebra.
- Ex. Displacement, velocity, acceleration, force, etc.
- A vector is represented by an arrow geometrically.
- Its length is proportional to its magnitude.
In vector algebra, we usually have four basic operations-
1. Addition of vectors
- Parallelogram laws
- Triangle laws &
- Polygon laws
2. Subtraction of vectors
3. Multiplication of vectors.
- Scalar or Dot product.
- Vector or Cross product.
4. Multiplication of vector with a scalar.
Explanation
- The product of two vectors may give you either scalar or vector quantity.
- It depends upon the operation through which it has obtained.
- In the case of the dot product of two vectors, it always gives you a scalar quantity. That's why it is also called the scalar product.
- While in the case of the vector or cross product, the result we obtain is a vector quantity.
Hence, option-3 is correct.
Product of Two Vectors
The product of two vectors is of two kinds
(i) scalar or dot product.
(ii) Vector or a cross product.
(i) Scalar or Dot Product
The scalar or dot product of two vectors A and B is denoted by A•B and is read as A dot B.
It is defined as the product of the magnitudes of the two vectors A and B and
the cosine of their included angle θ.
Thus, A•B = AB cosθ (a scalar quantity)
(ii) Vector or Cross Product
The cross product of two vectors A and B is denoted by A × B and read as A cross B.
It is defined as a third vector C whose magnitude is equal to the product of the
magnitudes of the two vectors A and B and the sine of their included angle θ.
Thus, if C = A × B, then C = AB sinθ.
The vector C is normal to the plane of A and B and points in the direction in which a right-handed screw would advance when rotated about an axis
perpendicular to the plane of the two vectors in the direction from A to B through the smaller angle θ between them or alternatively.