Which components are polarity sensitive and must be oriented correctly in a circuit?

• A. Electrolytic capacitors and diodes
• B. Resistors and capacitors
• C. Inductors and transformers
• D. Switches and fuses

Answer: (A)

Some components require a defined positive and negative direction to work correctly. The best example is electrolytic capacitors and diodes. Electrolytic capacitors are polarized, meaning one lead is the positive side and the other is the negative; connecting them with reverse polarity can damage the capacitor or cause it to fail spectacularly. Diodes conduct current in only one direction, so their orientation determines whether current can flow or is blocked in a given part of the circuit, which is essential for rectification and protection.

Other components listed are generally non-polar in behavior. Resistors and non-polar capacitors don’t have a preferred orientation, so flipping them doesn’t change their basic function. Inductors and transformers don’t rely on polarity for normal operation, though transformer windings do have a defined polarity for proper phasing in some circuits. Switches and fuses are passive devices that typically don’t care about which way they’re connected, aside from ensuring correct wiring and safety.