ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: NE2000 on July 09, 2009, 12:30:15 pm
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1. A magnet with north-end pointing down is allowed to fall through a coil of wire such that it can induce a current in the wire. It asks you to draw a graph of induced current against time. Would appreciate some help with this question. Thanks.
2. Also, just wanted to clarify, does increasing the number of coils on a DC motor increase the frequency of rotation because there are more forces acting in the upwards/downwards directions at once and hence greater torque overall for the motor? Does increasing the number of coils also increase the smoothness of the motor (say the coils are added in exactly the same plane)? I know that adding more coils in different planes will increase the smoothness.
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A2, yes F = nBIl increasing n increases the F which increases the rotational torque hence increases the speed which in turn decreases the period hence increases the frequency.