Electric fans, mixers, washing machines, computer drives, etc. Motors convert electrical energy into mechanical energy whereas generators convert mechanical energy into electrical energy.

The brushes are connected to the battery and touch the outer side of two halves of the split ring whose inner sides are insulated and attached to the axle.

The direction of current keeps on changing at frequent intervals in AC. Bu the direction of current always remains the same in DC. In India, the AC changes direction 100 times per second.

Fuse is used for protecting appliances due to short-circuiting or overloading. The fuse is rated for a certain maximum current and blows off when a current more than the rated value flows through it. If a fuse is replaced by one with larger ratings, the appliances may get damaged while the protecting fuse does not burn off. This practice of using fuse of improper rating should always be avoided.

Current carrying loops behave like bar magnets and both have their associated lines of field. This modifies the already existing earth’s magnetic field and a deflection results. Magnetic field has both direction and magnitude. Magnetic field lines emerge from N-pole and enter S-pole. The magnetic field strength is represented diagrammatically by the degree of closeness of the field lines. Field lines cannot cross each other as two values of net field at a single point cannot exist. Only one value, a unique net value, can exist. If in a given region, lines of field are shown to be parallel and equispaced, the field is understood to be uniform

Right hand thumb rule states that if a current carrying straight conductor is supposedly held in the right hand with the thumb pointing towards the direction of current, then the fingers will wrap around the conductor in the direction of the field lines of the magnetic field.

In a current carrying circular loop also the Right-Hand Thumb Rule is being obeyed. This means magnetic field lines are around the conducting wire. But circular shape of the conductor means that field lines at different points of the loop appear to be making ring around the periphery of the loop. It can be visualized like many small rings looping around the periphery of a big ring. Effect of Number of turns in a coil: If number of turns in coil is increased, then magnetic field has add on effect. Due to this, strength of magnetic field increases with increased number of turns in a coil.

 

Take a small rod (AB) of aluminium and suspend it with a stand; using two connecting wires.
• Take a horse-shoe magnet and keep it in a way that its magnetic field is in upward direction. For this, the north pole should be at the bottom and south pole should be at the top. The aluminium rod should be between the two poles of this magnet.


• Now connect the aluminium rod to a battery and plug key so that current flows through it
from B to A.
• You will notice that the aluminum rod moves towards left.
• Now, change the direction of current from A to B.
• In this case, the aluminium rod moves towards right.
In this experiment, direction of current and direction of magnetic field are mutually perpendicular. Direction of movement of aluminium rod is perpendicular to direction of current and direction of magnetic field.
Fleming’s Left-Hand Rule: If the thumb, index finger and ring finger of left hand are kept in mutually perpendicular direction then index finger shows the direction of magnetic field, ring finger shows the direction of electric current and thumb shows the direction of deflection in current carrying conductor. By using this rule, we can easily find the direction of deflection.