A closely packed coil having 1000 turns has an average radius of 62.8 cm. If current carried by the wire of the coil is 1 A, the value of magnetic field produced at the centre of the coil will be (permeability of free space $$ = 4\pi \times {10^{ - 7}}$$ H/m) nearly

The shape of the magnetic field lines due to an infinite long, straight current carrying conductor is

Two very long, straight, parallel conductors A and B carry current of 5 A and 10 A respectively and are at a distance of 10 cm from each other. The direction of current in two conductors is same. The force acting per unit length between two conductors is : ($$\mu$$_{0} = 4$$\pi$$ $$\times$$ 10^{$$-$$7} SI unit)

The magnetic field on the axis of a circular loop of radius 100 cm carrying current $$I = \sqrt 2 \,A$$, at point 1 m away from the centre of the loop is given by :