Heating Effect in Appliances Steps:

• Define heating effect: Electric current through a resistor produces heat via Joule's law (H = I²Rt).
• Identify appliance primary function: Check if it relies on heat generation for operation.
• Evaluate options: Eliminate those using electricity for motion or signals, not heat.
• Select match: Choose device with resistive heating element.

Why C is correct:

• Hairdryer uses a nichrome coil where current flow generates heat through resistance, per Joule's law, to dry hair.

Why the others are wrong:

• A: Cell phone powers circuits and screens for communication, not resistive heating.
• B: Fan drives a motor for blade rotation, converting electricity to mechanical energy.
• D: Lawnmower operates an electric motor for cutting, focusing on motion, not heat.

Final answer: C