Capacitors
MCAT glossary · Chemical & Physical Foundations of Biological Systems
Definition
Q = CV; energy U = ½CV^2 = ½QV; parallel C add, series: 1/Ceq = sum(1/Ci).
Capacitors in plain English
A capacitor is a tiny device that stores electric charge and releases it quickly, like a small rechargeable bucket for electricity that a camera flash uses to dump a burst of energy at once. How much charge it holds is Q = CV: the stored charge equals its capacitance C (its 'bucket size') times the voltage V (the electrical push), and the stored energy is U = 1/2CV^2. When you wire capacitors side by side (parallel) their capacitances simply add up, giving a bigger bucket; when you line them up end to end (series) the total shrinks, following 1/C_eq = sum (1/C_i). The pattern is the reverse of how resistors behave, so it's worth memorizing which is which.
Learn these first
Sign up free: all 171 MCAT terms as flashcards, plus practice questions with full explanations →
Related MCAT terms
MCAT practice questions · MCAT flashcards · MCAT study guide