InterviewSolution
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InterviewSolution
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Statethe characteristics of themagneticfidlproduced bya current - carryingcircularloop. Sketch its magnetic fieldlines. |
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Answer» Solution :Whena currentis passed through a circular loop , a magenticfield is produced aroundit . The patter fromedby the magnetic field line of themagneticfield due toacurrent - carrying circular loop is SHOWN in figure .  Themagnetic field lines of the fieldproducedby a current- carryingcircular loop are circularandconcentricnear the loop . As we move away from wire , theconcentriccircles representingthe magneticfieldaroundit becomesang larger . (The magnetic fieldis proportional to thecurrentand decreases as wemoveaway from the loop ). When we reachat the CENTREOF thecircularloop, the arcs of thesebig circles would apper as a straight line . Here every point on thecircularwire carrying currentwould give rise to the magnetic fieldapperingas straigth linesatthe magneticfield appearing as straight lines atthe centreoftheloop . By applyingthe Right- handthumb RULE ,it can be seen that every section of thewireproduces magneticfield/ field lines in the same direction within the loop. Hence , at the centre of the circular loop, all the magneticfield lines are in the same directionand aid each other due to which the strenght of themagneticfieldincreases. In caseof a current - carryingcircular coil havingN turns, the magneticfield produced is N times as large as that produced by a coil havingsingle turn ,assumingthat all turns havenearly the sameradius. Thisis because the currentin eachcircular turns has the samedirection and the fielddue to each turn then justadd up . Thus, magntidueof the magneticfield B produced at the centreof the coilis: (1) Directlyproportional to the currnetI flowingthrough it , i.e.,`B prop I` (2) Inversly proportional to theradiusr of the coil , i.e., `B prop (1)/(r)` . (3) Directly propotional to TOTAL NUMBEROF turns N of the coil , i.e., `B prop N ` . |
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