Correct Option
The correct option is (a).
Explanation
A hearing aid is a small, battery-operated electronic device worn in or behind the ear. It makes some sounds louder so that a person with hearing loss can listen, communicate, and participate more fully in daily activities. The device functions based on the principle of energy conversion using transducers.
Statement-wise Analysis
- Statement 1 is Correct: A hearing aid is an electronic device that requires a power source to function. It is operated by a small battery that powers the amplifier and other electronic components.
- Statement 2 is Incorrect: A microphone acts as an input transducer. Its function is to pick up sound waves from the environment and convert them into electrical signals. The statement incorrectly describes the function of a speaker.
- Statement 3 is Incorrect: A speaker (often called a receiver in hearing aids) acts as an output transducer. It receives amplified electrical signals and converts them back into sound waves, which are then directed into the ear canal. The statement incorrectly describes the function of a microphone.
Key Takeaway
A hearing aid follows the sequence: Microphone (Sound to Electrical) → Amplifier (Boosts Signal) → Speaker (Electrical to Sound). Microphones and speakers perform opposite energy conversions.