Why does the phase shift of the generator voltage and the EMF of the self-induction of the coil increase with increasing frequency?

Question

Electronics

The textbook shows it like this:


But in reality, the situation is different (yellow - generator (current), red - generator (voltage), green (self-induction EMF))

Frequency 20 Hz:


Frequency 1 kHz:


In the first case, the self-induction EMF is shifted by 90, in the second - is in antiphase to the external voltage. Why is the self-induction EMF not in antiphase with the external voltage in the first case?

Answer 1

the circuit contains active resistance (resistor) and reactive (inductance).
the angle of shift of the current flowing through the current circuit relative to the AC voltage applied to the circuit is proportional to the ratio of active and reactive resistance of the circuit.
the reactance of the coil to alternating current depends on the frequency.
The resistance of a resistor to AC is independent of frequency.
the reactance changes with frequency, which means that the shift angle will also change.