Capacitors are used in the following devices, except

Analyze the question: We need the device that does NOT use a capacitor. A capacitor stores electric charge and energy. In AC appliances it is used for starting motors, smoothing, and tuning.

Explain the concept: Capacitors are used in these ways:

• Capacitor-start or capacitor-run motors: Single-phase AC induction motors cannot start on their own. A capacitor creates a phase shift in the auxiliary winding to produce a starting torque.
• Smoothing and filtering circuits: Electronics convert AC to DC and use capacitors to smooth the output.
• Tuning and timing circuits: Radios and TVs use capacitors for tuning.

Check each option:

• A. Water pumping machines: These use single-phase induction motors, which have start or run capacitors. ✔ Uses a capacitor.
• B. Ceiling fans: The fan motor has a capacitor, which is why a fan can slow down or stop when the capacitor fails. ✔ Uses a capacitor.
• C. Electric irons: An iron is a purely resistive heating device. It has a heating element and a thermostat, with no need for a capacitor. ✘ Does not use one.
• D. Television sets: Their power supply and signal circuits contain many capacitors. ✔ Uses capacitors.

Answer: The device that does not use a capacitor is the electric iron, which is option C.

Tip: For "except" questions, ask whether the device has a motor or electronic circuit (it likely has a capacitor) or is just a heating element (it does not). Irons, kettles, and heaters are purely resistive.