Physics-
General
Easy

Question

A part of a long wire carrying a current i is bent into a circle of radius r as shown in figure. The net magnetic field at the centre O of the circular loop is

  1. fraction numerator mu subscript 0 end subscript i over denominator 4 r end fraction    
  2. fraction numerator mu subscript 0 end subscript i over denominator 2 r end fraction    
  3. fraction numerator mu subscript 0 end subscript i over denominator 2 pi r end fraction open parentheses pi plus 1 close parentheses    
  4. fraction numerator mu subscript 0 end subscript i over denominator 2 blank pi r end fraction open parentheses pi minus 1 close parentheses    

The correct answer is: fraction numerator mu subscript 0 end subscript i over denominator 2 pi r end fraction open parentheses pi plus 1 close parentheses


    The magnitude of the magnetic field at point O due to straight part of wire is
    B subscript 1 end subscript equals fraction numerator mu subscript 0 end subscript i over denominator 2 pi r end fraction
    B subscript 1 end subscript is perpendicular to the plane of the page, directed upwards (right hand plam rule 1).
    The field at the centre O due to the current loop of radius r is
    B subscript 2 end subscript equals fraction numerator mu subscript 0 end subscript i over denominator 2 r end fraction

    B subscript 2 end subscript is also perpendicular to the page, directed upwards (right hand screw rule).
    B subscript 1 end subscript plus B subscript 2 end subscript equals fraction numerator mu subscript 0 end subscript i over denominator 2 r end fraction open parentheses fraction numerator 1 over denominator pi end fraction plus 1 close parentheses
    equals fraction numerator mu subscript 0 end subscript i over denominator 2 pi r end fraction open parentheses pi plus 1 close parentheses

    Related Questions to study

    General
    physics-

    A wire shown in figure carries a current of 40 A. If r equals 3.14 blank c m, the magnetic field at point P will be

    A wire shown in figure carries a current of 40 A. If r equals 3.14 blank c m, the magnetic field at point P will be

    physics-General
    General
    physics

    A car covers one third part of its straight path with speed V1 and the rest with speed V2 . What is its average speed ?

    A car covers one third part of its straight path with speed V1 and the rest with speed V2 . What is its average speed ?

    physicsGeneral
    General
    physics

    A bus travels between two points A and B. V1 and V2 are it average speed and average velocity then

    A bus travels between two points A and B. V1 and V2 are it average speed and average velocity then

    physicsGeneral
    parallel
    General
    Maths-

    If f colon R not stretchy rightwards arrow R is defined by f left parenthesis x right parenthesis equals fraction numerator x squared minus 4 over denominator x squared plus 1 end fraction text  then  end text f left parenthesis x right parenthesis text  is  end text

    If f colon R not stretchy rightwards arrow R is defined by f left parenthesis x right parenthesis equals fraction numerator x squared minus 4 over denominator x squared plus 1 end fraction text  then  end text f left parenthesis x right parenthesis text  is  end text

    Maths-General
    General
    physics

    A car moving over a straight path covers a distance x with constant speed 10ms-1 and then the same distance with constant speed of V1.If average speed of the car is , 16 ms-1 then V2=...

    A car moving over a straight path covers a distance x with constant speed 10ms-1 and then the same distance with constant speed of V1.If average speed of the car is , 16 ms-1 then V2=...

    physicsGeneral
    General
    physics-

    A copper wire of negligible mass, 1 m length and cross-sectional area 10 to the power of negative 6 end exponent is kept on a smooth horizontal table with one end fixed. A ball of mass 1 kg is attached to the other end. The wire and the ball are rotated with an angular velocity 20 rads to the power of negative 1 end exponent. blankIf the elongation in the wire is 10 to the power of negative 3 end exponent m, then the Young’s modulus is

    A copper wire of negligible mass, 1 m length and cross-sectional area 10 to the power of negative 6 end exponent is kept on a smooth horizontal table with one end fixed. A ball of mass 1 kg is attached to the other end. The wire and the ball are rotated with an angular velocity 20 rads to the power of negative 1 end exponent. blankIf the elongation in the wire is 10 to the power of negative 3 end exponent m, then the Young’s modulus is

    physics-General
    parallel
    General
    physics-

    Two wires of equal cross-section but one made of steel and the other of copper are joined end to end. When the combination is kept under tension, the elongations in the two wires are found to be equal. What is the ratio of the lengths of the two wires? (Given : steel = 2 cross times 10 to the power of 11 end exponent N m to the power of negative 2 end exponent right parenthesis

    Two wires of equal cross-section but one made of steel and the other of copper are joined end to end. When the combination is kept under tension, the elongations in the two wires are found to be equal. What is the ratio of the lengths of the two wires? (Given : steel = 2 cross times 10 to the power of 11 end exponent N m to the power of negative 2 end exponent right parenthesis

    physics-General
    General
    physics-

    The relation between gamma comma eta and K for a elastic material is

    The relation between gamma comma eta and K for a elastic material is

    physics-General
    General
    Maths-

    If f colon R not stretchy rightwards arrow R is defined by f left parenthesis x right parenthesis equals fraction numerator x squared minus 4 over denominator x squared plus 1 end fraction then f left parenthesis x right parenthesis text  is  end text

    If f colon R not stretchy rightwards arrow R is defined by f left parenthesis x right parenthesis equals fraction numerator x squared minus 4 over denominator x squared plus 1 end fraction then f left parenthesis x right parenthesis text  is  end text

    Maths-General
    parallel
    General
    physics-

    Two long parallel conductors carry currents in opposite directions as shown. One conductor carries a current of 10 A and the distance between the wires is d=10cm  Current I is adjusted, so that the magnetic field at P is zero. P is at a distance of 5 cm to the right of the 10 A current. Value of I is

    Two long parallel conductors carry currents in opposite directions as shown. One conductor carries a current of 10 A and the distance between the wires is d=10cm  Current I is adjusted, so that the magnetic field at P is zero. P is at a distance of 5 cm to the right of the 10 A current. Value of I is

    physics-General
    General
    physics-

    Two long straight wires are set parallel to each other. Each carries a current i in the opposite direction and the separation between them is 2R. The intensity of the magnetic field midway between them is

    Two long straight wires are set parallel to each other. Each carries a current i in the opposite direction and the separation between them is 2R. The intensity of the magnetic field midway between them is

    physics-General
    General
    physics-

    A current of 10 A is passing through a long wire which has semicircular loop of the radius 20 cm as shown in the figure. Magnetic field produced at the centre of the loop is

    A current of 10 A is passing through a long wire which has semicircular loop of the radius 20 cm as shown in the figure. Magnetic field produced at the centre of the loop is

    physics-General
    parallel
    General
    physics-

    In the figure shown, the magnetic field induction at the point O will be

    In the figure shown, the magnetic field induction at the point O will be

    physics-General
    General
    physics-

    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

    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

    physics-General
    General
    physics-

    Current through ABC and A’ B’ C’ is I. What is the magnetic field at P? B P equals P B to the power of ´ end exponent equals r (Here C’ B’ PBC are collinear)

    Current through ABC and A’ B’ C’ is I. What is the magnetic field at P? B P equals P B to the power of ´ end exponent equals r (Here C’ B’ PBC are collinear)

    physics-General
    parallel

    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.