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Magnetic Field due to a Current Carrying Circular Loop

The demonstration given below explains the nature of magnetic field due to a current carrying circular loop.

 Procedure Observation Take a long wire and bend it to form a circle Concentric circles are formed, which are centred at the point where the wire passes through the cardboard Pass the wire through the cardboard such that half the wire is above it and the remaining part of the wire is below the cardboard The lines near the centre of the loop are almost straight. The magnetic field at the centre of the loop is perpendicular to the plane of the loop Join the free ends of the wire to a battery through a plug key The concentric circles become larger as we move away from the wire Insert the key and pass the current. Sprinkle iron filings on the cardboard and tap gently Note the pattern of the iron filings that emerge on the cardboard

 Procedure Observation Repeat the experiment by reversing the direction of flow of current The needle of the compass deflects in the opposite direction

 Procedure Observation Repeat the experiment by increasing the strength of the current On increasing the strength of current in the conducting wire, the number of lines of force around it increases

 Procedure Observation Repeat the experiment by increasing the number of turns of the coil The number of lines of force around the coil increases

 Procedure Observation Repeat the experiment by reducing the radius of the coil The number of lines of force around the coil increases

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