A uniform wire is bent in the form of a circle of radius `R`. A current `I` enters at `A` and leaves at `C` as shown in the figure :
If the length `ABC` is half of the length `ADC`, the magnetic field at the centre `O` will be

An infinite straight current carrying conductor is bent into a circle as shown in the figure . If the radius of the circle is R , the magnetic field at the centre of the coil is :

A long wire bent as shown in fig. carries current I. If the radius of the semicircular portion is a, the magnetic field at centre C is

A long wire bent as shown in fig. carries current I. If the radius of the semicircular portion is a, the magnetic field at centre C is

A current carrying wire is bent in the L shapes as shown in figure. The length of both arms extend to infinity. Then, the magnetic field at O is-

A current carrying wire is bent in the L shapes as shown in figure. The length of both arms extend to infinity. Then, the magnetic field at O is-

A wire A , bent in the shape of an arc of a circle , carrying current of 2 and having radius 2 cm and another wire B, also bent in the shape of arc of a circle , carrying a current of 3 A and having radius of 4 cm , are placed as shown in the figure . The ratio of the magnetic fields due to the wires A and B at the common centre O is :

A wire A , bent in the shape of an arc of a circle , carrying current of 2 and having radius 2 cm and another wire B, also bent in the shape of arc of a circle , carrying a current of 3 A and having radius of 4 cm , are placed as shown in the figure . The ratio of the magnetic fields due to the wires A and B at the common centre O is :