Which tool is designed for drilling holes using a battery pack?

The correct answer is a cordless drill, which is specifically designed to operate with a battery pack, allowing for portability and ease of use without the need for a power outlet. This feature makes it ideal for tasks where mobility is essential or where access to electricity is limited. Cordless drills typically come with rechargeable batteries, offering convenience and flexibility for various drilling applications.

On the other hand, an electric drill generally refers to any drill that requires a direct electrical connection to function, which may not be suitable for situations without immediate access to power. A pneumatic drill utilizes compressed air as its power source, making it unsuitable in contexts where battery-operated tools are preferred. Lastly, a hammer drill, while it may have cordless versions, is primarily identified by its hammering action for drilling into hard surfaces like concrete, which means it is not exclusively designated for battery power. Hence, the cordless drill stands out as the tool designed specifically for drilling holes using a battery pack.