| List I | List II |
| a) Opaque | 1.) Water |
| b) Transparent | 2.) Sun |
| c) Translucent | 3.) Wood |
| d) Luminous | 4.) Some plastics |
The question asks us to match different types of objects based on their light-transmitting properties (opaque, transparent, translucent) and light-emitting properties (luminous) with suitable examples. We need to understand the definitions of each term and identify the correct example for each.
Now let's match the given items:
Based on these matches:
This corresponds to the combination a-3, b-1, c-4, d-2.
B) The matching is a-3 (Opaque - Wood), b-1 (Transparent - Water), c-4 (Translucent - Some plastics), d-2 (Luminous - Sun). This option correctly pairs each term with its appropriate example.
The question asks which type of mirror can form a virtual image of a real object. We need to recall the image formation properties of plane, convex, and concave mirrors for real objects.
Correct Option: D) It may be plane or convex mirror
Both plane mirrors and convex mirrors always form virtual images when the object is real. A plane mirror forms a virtual image that is erect and of the same size. A convex mirror forms a virtual image that is erect and diminished. Therefore, either of these mirrors can form a virtual image of a real object.
The question asks to identify the correct statements comparing Blu-ray Discs (BD) with traditional DVDs. We need to evaluate each statement based on the technical specifications and capabilities of these optical disc formats.
The question asks to identify the principle where the angle of incidence equals the angle of reflection. This is a fundamental concept in optics related to how light behaves when it strikes a surface.
Correct Option: A) Law of reflection
The question asks about the type of reflection that occurs when light strikes a smooth, polished surface. We need to identify the term that correctly describes this phenomenon.
Correct Option: C) Regular reflection
When light is incident on a smooth, polished surface, the reflected rays travel in a definite direction, maintaining their parallelism. This phenomenon is called regular reflection. Mirrors are excellent examples of surfaces that exhibit regular reflection, producing clear, sharp images.
The question asks about the system used by visually impaired persons for reading and writing. We need to identify the specific method designed for this purpose.
Correct Option: A) Braille system is a widely recognized and effective method that allows visually impaired individuals to read and write using their sense of touch. It consists of raised dots arranged in cells, each representing a letter, number, or punctuation mark.