Identifying circuit components by symbols

Steps:

• Examine each circuit diagram for standard symbols: fuse (thin wire or rectangle with line), diode (triangle with bar).
• Check option A for presence of both symbols.
• Check option B for presence of both symbols.
• Check option C for presence of both symbols.
• Confirm option D shows both fuse and diode symbols.

Why D is correct:

• Circuit D includes a fuse symbol (protective device against overcurrent) and a diode symbol (one-way current valve per semiconductor definition).

Why the others are wrong:

• A lacks a diode, showing only a fuse and resistor.
• B has a diode but no fuse, featuring a battery and switch.
• C contains neither, with just a lamp and wires.

Final answer: D