A small planar probe coil is used to measure the axial magnetic field along the central axis of a high-performance superconducting solenoid. The plane of the probe coil is oriented perpendicular to the central axis.
The axial distance between the plane of the probe coil and the end of the solenoid is denoted by zzz. The graph below shows how the magnetic flux density B B\,B of the field varies with zzz.
The probe coil consists of 450 turns and has a cross-sectional area of 8.0 × 10-5 m2.
The probe coil is positioned at z=0.10 mz = 0.10 \text{ m}z=0.10 m. Show that the magnetic flux linkage through the probe coil is about 4.0×10−3 Wb4.0 \times 10^{-3} \text{ Wb}4.0×10−3 Wb.
The probe coil is now moved at a constant speed of 2.2 m s-1 along the axis so that z z\,z is increasing. An electromotive force (emf) is induced across the terminals of the probe coil. Explain what happens to the magnitude of the induced emf as the probe coil moves.
The probe coil passes through the position where z=0.15 mz = 0.15 \text{ m}z=0.15 m. Deduce whether the induced emf can exceed 50 mV for values of z z\,z greater than 0.15 m.