A C Motor
To understand the working of AC motor we have to understand, what happens when a current carrying conductor is kept in the magnetic field.
Activity
You can do a small activity to check this. The material required for this activity is a piece of wire, a battery of 9 Volt, a magnet and a key. Now note your observation a paper.
Now connect the battery with key and wire.
Keep the magnet close to the wire. makes you that they wire is perpendicular to the pole of magnet (if the pool and wire are parallel it will not work )
Close the key and observe the effect.
What did you get?
Following the point you may have observed:
So you will notice in your observation that when you close the key, the wire deflects from its position. When you will open the key, wire will come back to its original position.
It means whenever current flows in the wire, which is kept in magnetic field of the magnet. It experiences a force.
When current is zero force acting on the wire in magnetic field is also zero
How to find direction of force experienced by a current carrying while kept in magnetic field ?
We can find the direction of force experience by a current carrying wire kept in magnetic field by using Fleming's left hand rule?
Fleming's left hand rule is used to find the force acting on a current carrying conductor kept in kept in magnetic field.
This rule is also used in AC Motors to find the direction of force acting on the quality kept in magnetic field.
According to Fleming's left hand rule, “ stretch index finger, middle finger and thumb of your left hand perpendicular to each other (the position of hand is shown in diagram below), if your index finger points in the direction of magnetic field and middle finger points in the direction of current then Then your thumb points in the direction of force experience by the conductor in magnetic field.
What is an AC motor ? What is principle of AC motor? How it works ?
AC motor is a very simple device. It's very useful and very simple in design. AC motor is used in electric fan ,mixture, CD player , water pump , microwave oven, washing machine, etc. The parts of AC motor are: a movable coil mounted on a rotating axle, magnets, brushes, slip rings, connecting wires. A simple diagram of AC motor is shown in the image below .
Working of AC Motor:
As we can see in the image below, current enters from end A and goes to B, C and exits form D.
As the coil is kept in magnetic field, we can apply Fleming's left hand rule to find the direction of force experienced by part AB and part CD of the wire.
Direction of magnetic field is towards right. for end AB current is entering into the page so the direction of force experience bye the part AB is downward.
Similarly for part city current is coming out of the page buy a plan claiming left hand room we can see that the force acting on the part city of the wire is upward.
So we can see here ice the current enters from AB an exit from CD be part AB experiences force upward and part CD experiences force downward, it means required it set into the rotational motion.
After half of the rotation deposition off AB and see the interchange I'm the direction of current reverses in the coil because of the split rings.
Now AB is in place of CD and CD is in place of AB. In this case current enters from DC and exits from BA. Now we can apply Fleming's left hand rule to find the direction of force experience by the new position of coil.
This process of exchange in position of the coil continues still the current flows in coil. And motor keep working.
