(1) Constant flux $\neq$ zero flux — it means zero EMF ($d\Phi/dt = 0$). (2) Confusing $\Phi$ (flux) with $\varepsilon$ (EMF): flux can be large with zero EMF. (3) For rotating rods, the area swept per unit time is $l^2\omega/2$ (not $l^2\omega$). (4) Lenz's law gives the direction of induced current, not the magnitude. (5) Using the wrong formula: $M = k\sqrt{L_1 L_2}$ — forgetting $k$. (6) In LR circuits: inductor opposes change, so at $t = 0$ it has zero current (not maximum). (7) Energy in inductor is $LI^2/2$ — don't confuse with $LI$ or $LI^2$.