Which convention is used to represent currents and magnetic fields emerging out of a surface?

$A$ $10 \ A$ current is passing through a very long wire of radius $5 \ cm$. The magnetic field at a distance of $2 \ cm$ inside from its curved surface is . . . . . . $\times 10^{-5} \ T$.

$A$ wire is first bent in the form of a circular coil of $5$ turns and the same wire is then bent in the form of another circular coil of $10$ turns. If the same current is passed in both the coils,then the ratio of the magnetic fields at their centres is

An element $\Delta l = \Delta x \hat{i}$ is placed at the origin and carries a large current $I = 10 \; A$ (Figure). What is the magnetic field on the $y$-axis at a distance of $0.5 \; m$? Given $\Delta x = 1 \; cm$.

Magnetic field $dB$ due to a current element at any point on its axis is . . . . . . .

What is the magnetic field at point $P$ in the given figure?