Question Discussion & Solution

The correct answer is Mirage.

• To a distant observer, the light appears to be coming from somewhere below the ground.
• The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object.
• Such inverted images of distant tall objects cause an optical illusion to the observer.
• This phenomenon is called a mirage.
•  The optical illusion which occurs mainly in the desert during hot summer is based on the principle of TIR i.e total internal reflection.
• This type of mirage is especially common in hot deserts.

Additional Information

• Total Internal Reflection (TIR): When a ray of light goes from denser to the rarer medium it bends away from the normal and as the angle of incidence in denser medium increases, the angle of refraction in the rarer medium also increases and at a certain angle, angle of refraction becomes 90°, this angle of incidence is called critical angle (C).
• When the Angle of incidence exceeds the critical angle then the light ray comes back into the same medium after reflection from the interface. This phenomenon is called Total internal reflection (TIR).
• Conditions for TIR: 
  1. The ray must travel from denser medium to rarer medium.
  2. The angle of incidence 'i' must be greater than the critical angle C.

Given statement: pqrsq_st_stus_uvtuv_

Option 1 is following a pattern: pqrs / qrst / rstu / stuv / tuvw

Hence, ‘rrtw’ is the correct answer.

The correct answer is Rice.

• Rice blast disease, caused by Magnaporthe oryzae (Ascomycota), occurs in about 80 countries on all continents where rice is grown, in both paddy fields and upland cultivation.
• The extent of damage caused depends on environmental factors, but worldwide it is one of the most devastating cereal diseases, resulting in losses of 10–30% of the global yield of rice.
• Other common diseases of the crop of rice are - Blight, Bacterial leaf streak, Brown spot, Sheath blight, False smut, etc.

Additional Information

• The biological agents that causing diseases to plants are known as pathogens. 
• Some of the viral diseases in plants are - bud blight (soyabeans), Curly tops (Beans, tomato, etc.), Mosaic leaf (Tomato, pea, potato,tobacco, etc.).
• Some of the bacterial diseases in plants are - Blights (vegetable crops), Bacterial wilts (Tobacco, potatoes, etc), Cankers (Woody plants), Leaf Spots, Soft Wrots, etc.
• Some of the fungal diseases in the plants are - Cankers, Ergot, Rusts, Root rots, Scabs, Smuts, etc.
   

In a certain code language, 'CLASS' is written as 'DMBTT'.

Similarly, 'BLUE' written in that code language as

BLUE is related to CMVF.

Hence, "CMVF" is the correct answer.

The correct answer is BIOS.

BIOS is not a computer operating system.

Important Points

• BIOS (basic input/output system)
  • It is a program that is used by a computer's microprocessor to start the computer system after it is powered on.
  • It also manages data flow between the computer's operating system (OS) and attached devices, such as the hard disk, video adapter, keyboard, mouse and printer.

Key Points

• The Unix
  • A Unix family is a diverse group of operating systems, with sub-categories including System V, BSD, and Linux.
  • The name "UNIX" is a trademark of The Open Group which licenses it for use with any operating system that has been shown to conform to their definitions. 
• macOS 
  • It is an open core graphical operating system.
  • It is developed, and marketed, and sold by Apple Inc.
• Microsoft Windows
  • It is a family of proprietary operating systems designed by Microsoft Corporation.
  • It is primarily targeted at Intel architecture based computers.

Additional Information

• Operating system
  • An operating system (OS) is system software that manages computer hardware, software.
  • An operating system is a large and complex system.
  • OS system components include:
    • File,
    • Process,
    • Memory,
    • I/O device management.