Which of the following tools is primarily manual and not powered?

The putty knife is primarily a manual tool, designed for tasks such as spreading putty, paint, or other materials. It does not rely on any powered mechanism, making it suitable for precision work where control and finesse are required, like in painting or patching walls. Its simplicity and effectiveness in performing manual labor make it a fundamental tool in various trades, especially in construction and home improvement.

In contrast, the portable electric sander is powered by electricity, the PVC cutter is typically designed for cutting plastic pipes and may have manual levers but can also be found in powered versions, and a regular socket is used to connect and power tools but is not a tool in itself.