Question

The instrument which is based on the principle of optics is

• A. telescope
• B. television
• C. radar
• D. solar cell

Answer 1

The correct option is A

telescope

The explanation of the correct option:

Option A: Telescope

1. Optics is a branch of physics that deals with the study of light.
2. A telescope is a device that is used to detect objects that are located far away from the earth.
3. A telescope has two lenses, one for focusing light and another for magnifying the object.

The explanation of the incorrect options:

Option B: Television

1. Every television system uses the scanning principle pioneered by Nipkow's spinning disc scanner.
2. This converts a two-dimensional image into a time series of signals representing each resolvable element.

Option C: radar

1. Radar works by sending out short bursts of radio energy that are reflected off a target and returned as an echo.
2. Radar uses the ECHO PRINCIPLE, a well-known phenomenon.

Option D: solar cell

1. A solar cell is a device that directly converts the energy of light into electrical energy through the photovoltaic effect.

Hence, the correct option is ( A ), telescope.