Final answer:
A battery backup is the device that allows the use of gadgets when electricity fails. Generators and solar panels can also supply power, with solar output often needing an inverter to convert DC to AC for home use. The correct option is c) Battery Backup.
Step-by-step explanation:
When electricity fails, the device that allows you to continue using your gadgets is a battery backup. Battery backups store electrical energy and can provide power to devices during an outage. Generators and solar panels can also provide electricity in the absence of a grid supply, but they function differently.
A generator converts other sources of power into electrical energy, whereas solar panels convert light energy into electrical energy using semiconductors. However, the direct current (DC) output of solar cells typically needs to be converted into alternating current (AC) through an inverter, which is essential for most household appliances. Additionally, solar systems can be connected to the electrical grid to sell excess production back to the utility. The correct option is c) Battery Backup.