Answer / raseelrasheed

ANSWER IS SIMPLE....FAN IS A SINGLE PHASE INDUCTION
MOTOR....EVERY MOTOR HAVE FIELD AND ARMATURE,FIELD AND
ARMATURE ARE OPPOSING IN NATURE,SO FIELD TEND TO ROTATE
CLOCKWISE WHERE ARMATURE TEND TO ROTATE IN ANTI-CLKWISE.

IN CEILING FAN FIELD IS TAKEN AS STATIONARY AND ARMATURE
ALOWED TO ROTATE,SO ITS ROTATION IN ANTI CLKWISE,HENCE LEAF
CONNECTED TO ARMATURE IT ROTATE IN ANTI-LOCKWISE.

WHERE IN PEDESTRAL FAN,ARMATURE IS TAKEN AS FIELD ROTATING
AND ARMATURE STATIONARY,HENCE LEAF CONNECTED TO FIELD IT
ROTATE IN CLOCKWISE.

Answer / sarmadahmed

I hope you know about the right hand rule, for example if you rotate a screw anticlockwise it will loosen and when clockwise it tightens. Let the movement be the output whose direction can be determined by the right hand rule (curl=movement, face of thumb=direction of output).
By keeping this in mind, let the air (by the fan) be the output, ceiling fan is required to throw the air downward so these're made to rotate clockwise and exhaust fan is required to throw the air in the other direction, these're made to rotate counter clockwise.

Answer / engr. kashif

I get what ur trying to say by using the right hand rule and it does make sense. r u talkin about flemmings right hand rule...but that involves magnetic fields......then which rule is this?? some rule of aerodynaimcs is it.

Answer / vigneshwaran

because of polarities

Answer / sarmadahmed

That's a universal rule relating cause and effect, I screwed
this question from my daily observations, Fleming's rule is
the form of this universal rule for magnetic and electric
fields. But this law works everywhere, like screw, rolling belt, well bucket or alot of things.

hi can any body send me syllabus of rrb electrical section engg... and past pepar also of any board...

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