Question

what does this symbol indicate?

a grounded tool
b pneumatic tool
c powder actuated tool
d double insulated tool

Explanation:

Identify the symbol

The image shows a symbol consisting of a square inside another square.

Match symbol to standard definitions

In electrical engineering and tool safety standards (such as IEC 60417-5172), a square-in-a-square symbol represents Class II electrical appliances, which are double insulated.

Evaluate the given options

• (A) Grounded tool: Represented by a circle with three lines or a ground symbol.
• (B) Pneumatic tool: Typically represented by air pressure or hose symbols.
• (C) Powder actuated tool: Typically represented by warning symbols or cartridge icons.
• (D) Double insulated tool: Represented by the square-in-a-square symbol.

Answer:

• (A) Grounded tool
• (B) Pneumatic tool
• (C) Powder actuated tool
• (D) Double insulated tool (Correct answer)