Physics-
General
Easy

Question

PQ and RS are long parallel conductors separated by certain distance. M is the mid-point between them (see the figure). The net magnetic field at M is B. Now, the current 2A is switched off. The field at M now becomes

  1. 2B 
  2. B    
  3. fraction numerator B over denominator 2 end fraction    
  4. 3B    

The correct answer is: B


    Magnetic field at mid-point M in first case is B equals B subscript P Q end subscript minus B subscript R S end subscript
    left parenthesis therefore B subscript P Q end subscript a n d blank B subscript R S end subscript a r e blank i n blank o p p o s i t e blank d i r e c t i o n s right parenthesis
    equals fraction numerator 4 blank mu subscript 0 end subscript over denominator 4 pi d end fraction minus fraction numerator 2 blank mu subscript 0 end subscript over denominator 4 pi d end fraction equals fraction numerator 2 blank mu subscript 0 end subscript over denominator 4 pi d end fraction
    When the current 2 A is switched off, the net magnetic field at M is due to current 1 A
    B to the power of ´ end exponent equals fraction numerator mu subscript 0 end subscript cross times 2 cross times 1 over denominator 4 pi d end fraction equals B

    Related Questions to study

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.