Answer:
55.68 μT

0.12 mH
Magnetic flux and magnetic field
Step-by-step explanation:
i = Current = 40 mA
N = Number of turns = 435
D = Diameter of solenoid = 16.5 mm
l = Length of wire = 12.5 cm
A = Area of solenoid =

= Vacuum permeability =

Magnetic field of a solenoid is given by

The magnetic field inside the solenoid is 55.68 μT
Magnetic flux is given by

The magnetic flux through each turn is

Inductance of solenoid is given by

The inductance of the solenoid is 0.12 mH
As can be seen from the formulae above magnetic flux and magnetic field depend on current.