Chapter 19. Magnitude of magnetic torque on a current loop (19-8)

Question

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Question

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{"title":"Magnitude of the magnetic torque on a current loop","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"10,16,12,16\"},{\"shape\":\"poly\",\"coords\":\"144,22\"},{\"shape\":\"rect\",\"coords\":\"6,17,38,53\"}]"} {"title":"Magnitude of the magnetic field","description":"Correct!","type":"correct","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"143,6,176,52\"}]"} {"title":"Angle between the normal to the plane of the loop and the direction of the magnetic field vector B","description":"Incorrect","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"269,10,302,61\"}]"} {"title":"Area of the loop","description":"Incorrect","type":"incorrect","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"102,7,141,51\"}]"} {"title":"Current in the loop","description":"Incorrect","type":"incorrect","color":"#ff0000","code":"[{\"shape\":\"rect\",\"coords\":\"82,9,102,50\"}]"}

Question

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Question

Kxn/is+DK47MJaz6isAglzVzzZQ=
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Question

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{"title":"Magnitude of the magnetic torque on a current loop","description":"Wrong","type":"incorrect","color":"#99CCFF","code":"[{\"shape\":\"poly\",\"coords\":\"82,133\"},{\"shape\":\"rect\",\"coords\":\"10,16,12,16\"},{\"shape\":\"poly\",\"coords\":\"144,22\"},{\"shape\":\"rect\",\"coords\":\"6,17,38,53\"}]"} {"title":"Magnitude of the magnetic field","description":"Incorrect","type":"incorrect","color":"#ffcc00","code":"[{\"shape\":\"rect\",\"coords\":\"143,6,176,52\"}]"} {"title":"Angle between the normal to the plane of the loop and the direction of the magnetic field vector B","description":"Wrong","type":"incorrect","color":"#333300","code":"[{\"shape\":\"rect\",\"coords\":\"269,10,302,61\"}]"} {"title":"Area of the loop","description":"Incorrect","type":"incorrect","color":"#000080","code":"[{\"shape\":\"rect\",\"coords\":\"102,7,141,51\"}]"} {"title":"Current in the loop","description":"Correct!","type":"correct","color":"#ff0000","code":"[{\"shape\":\"rect\",\"coords\":\"82,9,102,50\"}]"}

Review

Although we’ve assumed a rectangular loop, Equation 19-8 applies to a current loop of area \(A\) of any shape.

Typically, the rotating coil in an electric motor is not just a single loop of wire, but has many turns (equivalent to many single coils stacked on top of each other). If a coil has \(N\) turns, the magnetic torque on it is \(N\) times greater than the value given by Equation 19-8.