What does the term magnetic field mean?
On Fig. 8.1, add an arrow on the axis of the solenoid to indicate the direction of the magnetic field inside the solenoid. Put the label P on this arrow.
State Lenz’s law.
Use Lenz’s law to state and explain the direction of the magnetic field due to the induced current in the small coil. On Fig. 8.1, show this direction with an arrow inside the small coil.
The small coil has a cross-sectional area of $7.0 \times 10^{-4}\,\text{m}^2$ and consists of $75$ turns of wire. A steady current in the solenoid produces a uniform magnetic flux of flux density $1.4\,\text{mT}$ throughout the small coil. The current in the solenoid is reversed over $0.12\,\text{s}$. Calculate the average e.m.f. induced in the small coil.