Remain almost constant From the Biot-Savart law, magnetic field (B) at a point P close to the wire carrying current i is given by,B =4πμ0​​r3idl×r​Magnetising field intensity (H) will be,H=μ0​B​ = 4π1​r3idl×r​Now, as the cylindrical rod is brought close the wire such that centre of the rod is at P, then distance of point P from the wire(r) will remain same. Hence, magnetic field intensity will remain almost constant. Also even when the rod is carrying any current then B will be zero at the centre of the rod so the value of Magnetising field intensity will remain the same at point P.