Magnetic field due to current carrying conductor

 

Magnetic field due to current carrying conductor

 

To find the magnetic field in the current carrying conductor , we should Take a long straight copper wire, and battery or cell (two or three cells of having 1.5 volts) and one plug key . Now connect them in the form of series connection of the circuit.   And now put the compass needle parallel to the straight  copper wire. Now, when the circuit is completed , we found that there is deflection of the north pole of the needle of the compass. When the current is passed from north to south , then the north pole of the needle get defected towards to the east direction.

But when the direction of the current flowing through the copper wire is changed , then there is change of the direction of the deflection of the needle of the compass. We found that needle moves in opposite direction that is towards the west directions.

Then it means that the direction of the magnetic field produces by the electric current in the circuit is also reversed.

 

 

 

 

 

 

 

 

Magnetic field due to a current through a straight conductor

 

 

 

To find the magnetic field in the current carrying conductor , we should take a variable resistance , an ammeter (0-5 A), a cell or a battery (12 V) , a plug, connecting wires and a long straight thick copper wire.

Put the thick wire at the center to the normal to the plane of the rectangular cardboard. And cardboard should be fixed. And make the circuit in series with the help of the cell , plug key , variable resistance.  connect the copper wire vertically with the circuit. And iron fillings is sprinkled on the plane cardboard. And when the circuit get completed , we tap the cardboard for few times. We observe the pattern of the iron fillings. we found that a pattern of the concentric circles around the vertical wire is aligned by the iron fillings. these concentric iron fillings represented as the magnetic field lines.

Now if we want to find out the direction of the magnetic field , then we should put the compass over a circle. Then we observe that the direction of the north pole of the compass needle gives the direction of the field lines produced by the electric current through the straight wire.

 

Point to noted that if the current in the copper wire gets changed , then the deflection of the compass needle is also changed.

It means , if the current is increased then the deflection of the compass needle  is also increased.

It means that at a given point  when  the current flowing through the  wire increases , then  the magnitude of the magnetic field produced  also increases.

 

When the compass moves away from the copper wire but having the same current flowing through the wire then we found that the deflection of compass needle also decreases.

It means that as the distance from the current carrying wire increases then the magnetic field produced by such conductor or wire gets decreases.