Which of the following is an electrical safety device specifically designed to protect sensitive electrical equipment from sudden voltage spikes and surges in the supply?

Introduction / Context:
Modern homes and offices use many electronic devices such as computers, televisions, routers, and chargers that can be damaged by sudden voltage spikes on the power line. Electrical engineering and basic physics general knowledge questions often ask about the specific devices used to guard against such overvoltage events. This question focuses on identifying the correct protective device from a set of similar sounding options.

Given Data / Assumptions:
- Electrical devices are connected to a power supply that may experience voltage spikes.- The goal is to protect the equipment from damage due to transient overvoltages.- Several device names are listed, but only one is a standard term used in power protection.

Concept / Approach:
Voltage spikes, also called surges, are short duration increases in voltage that can occur due to lightning strikes, switching of heavy loads, or faults in the power system. A surge protector is a device specifically designed to limit the voltage supplied to an electrical appliance by either blocking or shorting to ground any unwanted voltages above a safe threshold. The other names in the options are either not standard terms or refer to different kinds of protection and therefore do not correctly describe the device used against voltage spikes.

Step-by-Step Solution:
1. Recognise that the key phrase in the question is voltage spikes and the need to protect devices.2. Recall that the widely used term for such equipment is surge protector, often seen as power strips with built in protection.3. Compare this with the other options, which do not correspond to common industry terminology.4. Identify surge protector as a device specifically engineered to handle voltage surges.5. Conclude that surge protector is the correct choice that matches the description in the question.

Verification / Alternative check:
If you look at the specifications on many power strips or extension boards sold for computer equipment, they are labelled surge protectors and list a surge energy rating in joule. This marketing and technical usage confirms that the accepted name for devices protecting against voltage spikes is surge protector. No standard product is sold as a voltage unloader or current unloader in this context, which supports the identification of the correct option.

Why Other Options Are Wrong:
- Voltage unloader: This term is not a standard electrical engineering term and does not correspond to a recognised protective device.- Heat protector: This might describe thermal cut outs or thermostats that respond to temperature, not directly to voltage spikes.- Current unloader: Again, this is not a commonly used term and does not specifically refer to surge protection for overvoltage events.

Common Pitfalls:
Students sometimes get confused by unfamiliar but impressive sounding terms and may choose them over the correct, simpler name. In exam situations, it helps to trust the terms you have seen on real equipment and in textbooks. Surge protector is a widely used and easily verified name, which should make it stand out as the correct answer for this question.

Final Answer:
The device designed to protect electrical devices from voltage spikes is a surge protector.