Answer

Correct option: (ii) Converting physical quantities into digital data

Explanation

A Data Acquisition (DAQ) system collects real-world physical signals and converts them into a form that a computer or microcontroller can process.

A typical DAQ sequence is:

Physical quantity → Sensor → Signal Conditioning → ADC → Digital Data → Processing/Storage

For example, a temperature sensor produces an electrical signal corresponding to temperature. The signal is conditioned if required and then converted into a digital value by an Analog-to-Digital Converter (ADC).

Why the other options are incorrect

• (i) Data storage: Storage may be included in a DAQ system, but it is not its primary purpose.
• (iii) Wireless communication: Wireless communication may be used for transmitting acquired data, but it is not the fundamental purpose of DAQ.
• (iv) Power amplification: Power amplification is not the primary function of a DAQ system.

Therefore, the correct answer is (ii).