A 5.40 10-5 H solenoid is constructed by wrapping 65 turns of wire around a cylinder

Question:

A 5.40 × 10-5 H solenoid is constructed by wrapping 65 turns of wire around a cylinder with a cross sectional area of 9.0 × 10-4 m2. When the solenoid is shortened by squeezing the turns closer together, the inductance increases to 8.60 × 10-5 H. Determine the change in the length of the solenoid.