Which device provides protection against short circuits and overloads?

• A. RCCB
• B. RCBO
• C. MCB
• D. Bonding conductor

Answer: (C)

Overcurrent protection is provided by a device that trips when current becomes too high. An MCB does this with two built-in mechanisms: a thermal element that reacts to prolonged overloads and a magnetic element that trips instantly on a short circuit. This combination directly protects conductors and equipment from damage due to excessive current, which is exactly what’s meant by protection against short circuits and overloads. An RCBO would also provide this protection, but it adds residual-current (earth leakage) protection as well, which isn’t required to meet the stated need. RCCBs focus on leakage detection and don’t address overcurrent, and bonding conductors don’t interrupt fault currents. So, the MCB is the most direct and appropriate choice for protecting against short circuits and overloads.