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QJEEM21Ph365e: JEE Main 2021 Physics - Class 12 JEEM21Ph365e Solution: A current of 1.5 A is flowing through a triangle, of side 9 cm…

A current of 1.5 A is flowing through a triangle, of side 9 cm each. The magnetic field at the centroid of the triangle is :

(Assume that the current is flowing in the clockwise direction.)

Multiple Choice Options

  • A 3 ×\times 10 −- 7 T, outside the plane of triangle
  • B 232\sqrt 3 ×\times 10 −- 7 T, outside the plane of triangle
  • C 232\sqrt 3 ×\times 10 −- 5 T, inside the plane of triangle
  • D 3 ×\times 10 −- 5 T, inside the plane of triangle

Step-by-Step Verified Solution

JEE Main 2021 (Online) 31st August Evening Shift Physics - Magnetic Effect of Current Question 105 English Explanation

B=3[μ0i4πr(sin⁡60∘+sin⁡60∘)]B = 3\left[ {{{{\mu _0}i} \over {4\pi r}}(\sin 60^\circ + \sin 60^\circ )} \right]

tan⁡60∘=l/2r\tan 60^\circ = {{l/2} \over r}

where r=9×10−223r = {{9 \times {{10}^{ - 2}}} \over {2\sqrt 3 }} M

∴\therefore B = 3 ×\times 10-5 T

Current is flowing in clockwise direction so, B→\overrightarrow B is inside plane of triangle by right hand rule.

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