单选题 The analogy between electrical and _____ systems helps beginners understand current flow as fluid movement.

单选题 The energy stored in a capacitor is measured in _____.

单选题 The _____ clearly shows how all components are interconnected in the circuit.

单选题 A _____ allows current to flow only in one direction.

单选题 Before connecting a capacitor, always confirm its _____ to prevent damage.

单选题 In circuit analysis, all components connected to the same electrical _____ form a single voltage reference point.

单选题 When applying KVL, the voltage drops must be added using their correct _____ signs.

单选题 In an electrolytic capacitor, the positive _____ is made of aluminum foil coated with oxide.