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Current density (vecJ) in an area of cro...

Current density `(vecJ)` in an area of cross section `vecA=(2hati+3hatj)cm^2 " is " vecJ=(8hati+2hatj)A//m^2` . Current through the area is

A

22 mA

B

2.2 mA

C

11 mA

D

1.1 mA

Text Solution

Verified by Experts

The correct Answer is:
B
Use `i=vecJ.vecA`
Since `i=vecJ.vecA = (8hati+2hatj).(2hati+3hatj)xx10^(-4)`
`=(16+6)xx10^(-4) A = 2.2 mA`
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Knowledge Check

  • If vecA=4hati+6hatj and vecB=2hati+3hatj . Then

    A
    `vecA.vecB=29`
    B
    `vecAxxvecB=vec0`
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    D
    angle between `vecA` and `vecB` is `30^@`

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    B
    10 units
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    D
    `sqrt(61)` units

  • What is the area of the triangle formed by sides vecA = 2hati -3hatj + 4 hatk and vecB= hati - hatk

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    `sqrt(13.5)` unit
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    `sqrt(38.7)` unit
    D
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