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 :

A long solenoid of radius 1 mm has 100 turns per mm. If 1 A current flows in the solenoid, the magnetic field strength at the centre of the solenoid is