Current Loop in Uniform Magnetic Field – Internal Forces – Rankers Physics

Magnetic Field Due to Straight Current Carrying Wire: Practice Problem & Solution

Assertion (A): If a uniform current carrying loop is placed in uniform magnetic field perpendicular to plane of loop. Tension or compression is created in loop. Reason (R): Net force on any closed loop in uniform magnetic field is zero.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Magnetic Field Due to Straight Current Carrying Wire. Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true: Magnetic forces \(I d\vec{l} \times \vec{B}\) on segments act radially, causing tension or compression. Reason (R) is true: For a uniform \(\vec{B}\), \(\vec{F}_{net} = I \oint d\vec{l} \times \vec{B} = 0\). However, zero net translational force does not explain the internal tension/compression. Both are true, but (R) is not the explanation for (A).

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