MDCAT Alternating Current MCQs 2026 | ICE, ELI, EM Spectrum

Phase, ICE/ELI, $X_C,X_L$, capacitors as DC blocks, inductors as chokes, and the EM spectrum at c.

No. c is the same. Higher f is shorter $\lambda$. In vacuum $c=f\lambda$, so a frequency increase is accompanied by a wavelength decrease. In a material, speed depends on the medium and can depend on frequency.

In a capacitor, I leads E (voltage). ELI: in an inductor, E leads I, so current lags. The phase difference is $90^{\circ }$ for ideal pure capacitive or inductive circuits. In circuits that also contain resistance, find the actual phase angle rather than applying the ideal mnemonic unchanged.

DC is $f=0$, so $X_C$ = 1/($\omega C$) → ∞. No current in the steady state. A capacitor can carry a transient charging current immediately after connection. The zero-current statement applies to the steady state of an ideal capacitor, not the initial charging interval.

No. Sound is a mechanical wave in a medium. Radio to gamma are EM, all at c in vacuum. Sound requires a material medium and cannot propagate through a vacuum. Electromagnetic waves do not require a material medium and differ in frequency, wavelength and photon energy.

The current Alternating Current question bank contains 425 practice MCQs across 3 topics. This is the bank size, not the length of one test. Choose your topics and a question count from 1 to 180, limited by the questions available in those topics.

The selectable topics are AC Phase, AC Circuits, EM Spectrum. Use Select all for a broad chapter drill, Clear to start a focused selection, or choose individual topics. Questions are drawn from your chosen topics, so you can target a weak concept before returning to a wider test.

Open the chapter builder, select one or more topics, enter your question count, and choose Tutor Mode or Timed Exam. The available-question total updates with your selection. Start Test generates a shuffled drill; you do not have to follow a fixed Quiz 1 or Quiz 2 sequence.

Tutor Mode gives feedback and an explanation after you choose an option, and you can change or clear that choice. Timed Exam runs a countdown and keeps explanations hidden until submission. Both modes let you move between questions, use the paper map, and submit for a complete review.

Select Submit Quiz, then Submit & View Explanations. The review includes every question in your test, all options, your selection, the marked correct answer when a key is available, and the explanation. Download PDF saves a paginated review; Download Review saves an HTML copy you can open in a browser. The review also includes DIFF. MDCAT community links.

Start with a short tutor drill on one of these topics: AC Phase, AC Circuits, EM Spectrum. Read the explanation for incorrect and uncertain answers, revise the relevant textbook section, and retry before taking a timed drill. Compare your reasoning with the answer key rather than memorising the option letter.