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The magnitude of the vector product of t...

The magnitude of the vector product of two vectors and may be : `overset(rarr)A` and `overset(rarr)B`

A

greater than AB

B

equal to AB

C

less than AB

D

equal to zero

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The correct Answer is:
To solve the problem of determining the magnitude of the vector product of two vectors \( \vec{A} \) and \( \vec{B} \), we can follow these steps: ### Step 1: Understand the Vector Product The vector product (or cross product) of two vectors \( \vec{A} \) and \( \vec{B} \) is defined as: \[ \vec{A} \times \vec{B} = |\vec{A}| |\vec{B}| \sin \theta \, \hat{n} \] where \( \theta \) is the angle between the two vectors, and \( \hat{n} \) is the unit vector perpendicular to the plane containing \( \vec{A} \) and \( \vec{B} \). ### Step 2: Calculate the Magnitude of the Vector Product The magnitude of the vector product is given by: \[ |\vec{A} \times \vec{B}| = |\vec{A}| |\vec{B}| \sin \theta \] ### Step 3: Analyze the Range of \( \sin \theta \) The sine function varies between -1 and 1. Therefore, the value of \( |\sin \theta| \) can range from 0 to 1. This leads us to the following conclusions: - If \( \theta = 0 \) or \( \theta = \pi \) (the vectors are parallel), then \( \sin \theta = 0 \) and hence \( |\vec{A} \times \vec{B}| = 0 \). - If \( \theta = 90^\circ \) (the vectors are perpendicular), then \( \sin \theta = 1 \) and \( |\vec{A} \times \vec{B}| = |\vec{A}| |\vec{B}| \). ### Step 4: Establish Relationships From the above analysis, we can establish that: \[ 0 \leq |\vec{A} \times \vec{B}| \leq |\vec{A}| |\vec{B}| \] This means the magnitude of the vector product is always less than or equal to the product of the magnitudes of the two vectors. ### Step 5: Conclusion Based on the analysis, we can conclude: - The magnitude of the vector product \( |\vec{A} \times \vec{B}| \) can be equal to 0 (when vectors are parallel). - The magnitude can be less than \( |\vec{A}| |\vec{B}| \) (when the angle is not 90 degrees). - The magnitude can be equal to \( |\vec{A}| |\vec{B}| \) only when the vectors are perpendicular. Thus, the possible answers are: - Less than \( |\vec{A}| |\vec{B}| \) - Equal to \( |\vec{A}| |\vec{B}| \) when \( \theta = 90^\circ \) - Equal to 0 when \( \theta = 0 \) or \( \theta = \pi \) ### Final Answer The magnitude of the vector product of two vectors \( \vec{A} \) and \( \vec{B} \) can be: - Less than or equal to \( |\vec{A}| |\vec{B}| \) - Equal to 0

To solve the problem of determining the magnitude of the vector product of two vectors \( \vec{A} \) and \( \vec{B} \), we can follow these steps: ### Step 1: Understand the Vector Product The vector product (or cross product) of two vectors \( \vec{A} \) and \( \vec{B} \) is defined as: \[ \vec{A} \times \vec{B} = |\vec{A}| |\vec{B}| \sin \theta \, \hat{n} \] where \( \theta \) is the angle between the two vectors, and \( \hat{n} \) is the unit vector perpendicular to the plane containing \( \vec{A} \) and \( \vec{B} \). ...
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Knowledge Check

  • Dot product of two vectors overset(rarr)A and overset(rarr)B is defined as overset(rarr)A.overset(rarr)B=aB cos phi , where phi is angle between them when they are drawn with tails coinciding. For any two vectors . This means ovsert(rarr)A . overset(rarr)B=overset(rarr)B. overset(rarr)A that . The scalar product obeys the commutative law of multiplication, the order of the two vectors does not matter. The vector product of two vectors overset(rarr)A and overset(rarr)B also called the cross product, is denoted by overset(rarr)A xx overset(rarr)B . As the name suggests, the vector product is itself a vector. overset(rarr)C=overset(rarr)A xx overset(rarr)B then C=AB sin theta , For non zero vectors overset(rarr)A, overset(rarr)B, overset(rarr)C,|(overset(rarr)Axxoverset(rarr)B).overset(rarr)C|=|overset(rarr)A||overset(rarr)B||overset(rarr)C| holds if and only if

    A
    `overset(rarr)A.overset(rarr)B=0,overset(rarr)B.overset(rarr)C=0`
    B
    `overset(rarr)B.overset(rarr)C=0,overset(rarr)C.overset(rarr)A=0`
    C
    `overset(rarr)C.overset(rarr)A=0,overset(rarr)A.overset(rarr)B=0`
    D
    `overset(rarr)A.overset(rarr)B=overset(rarr)B.overset(rarr)C=overset(rarr)C.overset(rarr)A=0`
  • Dot product of two vectors overset(rarr)A and overset(rarr)B is defined as overset(rarr)A.overset(rarr)B=aB cos phi , where phi is angle between them when they are drawn with tails coinciding. For any two vectors . This means overset(rarr)A . overset(rarr)B=overset(rarr)B. overset(rarr)A that . The scalar product obeys the commutative law of multiplication, the order of the two vectors does not matter. The vector product of two vectors overset(rarr)A and overset(rarr)B also called the cross product, is denoted by overset(rarr)A xx overset(rarr)B . As the name suggests, the vector product is itself a vector. overset(rarr)C=overset(rarr)A xx overset(rarr)B then C=AB sin theta , overset(rarr)A=hat i+ hat j-hatk and overset(rarr)B=2 hat i +3 hat j +5 hat k angle between overset(rarr)A and overset(rarr)B is

    A
    `120^(@)`
    B
    `90^(@)`
    C
    `60^(@)`
    D
    `30^(@)`
  • Dot product of two vectors overset(rarr)A and overset(rarr)B is defined as overset(rarr)A.overset(rarr)B=aB cos phi , where phi is angle between them when they are drawn with tails coinciding. For any two vectors . This means overset(rarr)A . overset(rarr)B=overset(rarr)B. overset(rarr)A that . The scalar product obeys the commutative law of multiplication, the order of the two vectors does not matter. The vector product of two vectors overset(rarr)A and overset(rarr)B also called the cross product, is denoted by overset(rarr)A xx overset(rarr)B . As the name suggests, the vector product is itself a vector. overset(rarr)C=overset(rarr)A xx overset(rarr)B then C=AB sin theta , A force overset(rarr)F=3hat i +c hat j + 2 hatk acting on a particle causes a displacement d=4hat i+ 2 hat i + 3 hat k . If the work done (dot product of force and displacement) is 6J then the value of c is :

    A
    12
    B
    0
    C
    6
    D
    1
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