torque (1 Viewer)

[red802]

Explaiin why there is no torque on the coil when it is 90 degrees. but can soeone explain because i understand the method BIAcos90 = minimum torque, but why does it have no torque

 

[PLooB]

Because the two conductors experience a force away from the rotor and the resultant force is 0 because they both cancel each other out. The momentum and the change in direction of the current keeps it going when it reaches this point.

Sorry for the confusion, fixed now.

 

[A l]

Note that theta is the angle between magnetic field and loop of wire. When theta is 90 degrees the magnetic field passes right through the loop made by the wire and doesn't pass through the wire itself, so the wire has no changing magnetic field, hence no torque. Whereas, on the other hand if theta was say 0 degrees, the magnetic field would pass through the wire itself directly so the torque is at maximum.

 

[Mono!]

Explaiin why there is no torque on the coil when it is 90 degrees. but can soeone explain because i understand the method BIAcos90 = minimum torque, but why does it have no torque

When its @ 90 degrees isnt it @ its strongest when its parallel to the magnetic field there no torque isnt it?

 

[Mono!]

http://hsc.csu.edu.au/physics/core/motors/2578/phy931.html hope this is sone help

 

[Mountain.Dew]

When its @ 90 degrees isnt it @ its strongest when its parallel to the magnetic field there no torque isnt it?

realise that when theta = 90 degrees, both sides of the coil are forced AWAY from each other. in this sense, the resultant net force is 0, and so, there is no torque, following the basic principle torque = Fd. F = 0, so torque = 0.

PLoob, when the two sides of the coil are forced TOWARDS the rotor, that is, towards each other, THEN the coil will rotate. this only happens because of the sudden change in the direction of current when theta = 90, either because of the nature of AC, or, because of the split-commutator in DC motors.

 

[Dragie]

Cos90 = 0,
So mathematically nBIA multiplied by 0 is 0. Theoretically, the sides of the rotor cancel each other out (because they are opposite and the net force on the rotor is 0). When it is parallel, cos0 = 1, therefore it is maximum.