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I know how to find the magnetic dipole and solved it to be (10A)(0.005 m^2) = 0.05 in the -z direction. However, the next part of the question asks to find the magnitude and direction of the torque and this is where I get confused. I've attached my work below. The angle between the dipole and the mag. field I calculated as 150 degrees, so I got a net positive torque in the y direction. However, the answer key says its in the negative y direction. Am I missing something?

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  • $\begingroup$ Hi and welcome to the Physics SE! Please note that we don't answer homework or worked example type questions. Please see this page in the site help for more on what topics you can ask about here. $\endgroup$
    – John Rennie
    Commented Mar 28, 2019 at 5:28
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    $\begingroup$ @JohnRennie I've literally worked out the entire question...my work is shown. I'm not asking you to give me answers considering I have the answer key. I'm asking for clarification if I did the steps correctly since they don't correspond with the answer key. $\endgroup$
    – Hopper
    Commented Mar 28, 2019 at 5:38
  • $\begingroup$ You can find the direction directly by the direction of $\vec m X \vec B$ by right hand thumb rule $\endgroup$
    – Eagle
    Commented Mar 28, 2019 at 6:31

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The angle between $\mu$ and $\vec B$ is $210^\text{o}$ not $150^\text{o}$. We measure angle anti-clockwise from the initial to final vector. So in the cross product $\mu \times \vec{B}$, we measure the angle from $\mu$ to $\vec{B}$ anti-clockwise

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    $\begingroup$ Thanks! I had a feeling that my angle was off and the reason for me not getting a negative value. Thank you for clarifying this for me. $\endgroup$
    – Hopper
    Commented Mar 28, 2019 at 7:23

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