General Knowledge (Part – B : english) (NDA/NA SOLVED PAPER 2021-I) (51 to 100)

Total Questions: 50

21. Squamous epithelial cells are found in the inner lining of

Correct Answer: (a) Oesophagus.
Solution:
  • Squamous epithelial cells are flat and are usually found lining surfaces that require a smooth flow of fluid, such as your blood vessels.
  • They also line areas that require a very thin surface for molecules to pass through, such as the air sacs in your lungs.
  • Squamous epithelium has cells that are wider than their height (flat and scale-like).
  • This is found as the lining of the mouth, oesophagus, and including blood vessels and in the alveoli of the lungs.

22. Transformation of meristematic cells into specific permanent tissues occurs by the process of

Correct Answer: (a) Cell differentiation.
Solution:
  • The permanent tissues always differentiate from the meristematic cells, during the process of growth. These meristematic cells lose the ability to divide and take up a specific role. This process of taking up a permanent shape, size and a function is called cellular differentiation.
  • The cells derived from root apical and shoot-apical meristems and cambium differentiate and mature to perform specific functions.
  • This act leading to maturation is termed as differentiation. During differentiation, cells undergo few to major structural changes both in their cell walls and protoplasm.
  • The living differentiated cells, that by now have lost the capacity to divide can regain the capacity of division under certain conditions. This phenomenon is termed as dedifferentiation.
  • For example, formation of meristems-interfascicular cambium and cork cambium from fully differentiated parenchyma cells. While doing so, such meristems/tissues are able to divide and produce cells that once again lose the capacity to divide but mature to perform specific functions, i.e., get redifferentiated.

23. The gaseous product of a process in plants is a requirement for another vital process that releases energy. Given below are four combinations of the process and product. Identify the correct answer.

Correct Answer: (c) Photosynthesis and Oxygen
Solution:Plants produces oxygen through photosynthesis process and prepare their food for survival. The oxygen is used in the respiration process which takes place mitochondria of the cell.

24. In a dicot pot herb, vaseline/vegetable oil was applied on the upper surface of one leaf (Experimental leaf 1) and on the lower surface of another leaf (Experimental leaf 2). Vaseline/Vegetable oil was not applied on the control leaf. The plant was deliberately not watered for several days. Which leaf will dry up last?

Correct Answer: (b) Experimental leaf 2
Solution:
  • In this experiment, Vaseline was applied to the upper surface of one leaf (Experimental leaf 1) and the lower surface of another (Experimental leaf 2), while a control leaf had no application.
  • When a plant lacks water for several days, it relies on moisture in its leaves, and the oil creates a barrier that reduces water loss through transpiration.
  • Experimental leaf 2, with oil on its lower surface, will dry up last, while Experimental leaf 1 will dry up faster due to oil on its upper surface. The control leaf will dry up the fastest, as it has no barrier.
    Therefore, the correct answer is option 2: Experimental leaf 2 will dry up last.

25. Which one of the following statements is not correct for light rays?

Correct Answer: (c) Light speeds down as it leaves a water surface and enters the air.
Solution:
  • A light ray is a line (straight or curved) that is perpendicular to the light's wavefronts; its tangent is collinear with the wave vector. Light rays in homogeneous media are straight. They bend at the interface between two dissimilar media and may be curved in a medium in which the refractive index changes
  • Light waves travel fastest through a vacuum and air, and slower through other materials such as glass or water. Light travels at approximately 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows down to 225,000 kilometers per second in water and 200,000 kilometers per second in glass.

26. A glass prism splits white light into different colours. This phenomenon is called dispersion of light by prism. Which one of the following statements is correct?

Correct Answer: (b) Violet light will deviate the most and it is because of the refraction of light.
Solution:Rayleigh scattering law. It simply states that :
1. U(Refractive index) is inversely proportional to square of the wavelength of light.
2. deviation is directly related to refractive index.
3. Speed of light depends on the medium. Densser the medium lesser the speed and raser the medium greater the speed of light and is maximum 3 × 10ᵉ m/s in air/vacuum.
More the index more will be the deviation
  • Violet colour deviate most and red deviate the less because the wavelength of a red light is almost double the wavelength of violet light.
  • Because of the different indices of refraction for the different wavelengths of visible light, the angle of deviation varies with wavelength. But since the violet light has a shorter wavelength, it would refract more than the longer wavelength red light.

27. A current of 1.0 A is drawn by a filament of an electric bulb for 10 minutes. The amount of electric charge that flows through the circuit is

Correct Answer: (c) 600 C
Solution:

28. Which one of the following formulas does not represent electrical power?

Correct Answer: (b) IR²
Solution:

29. The sound created in a big hall persists because of the repeated reflections. The phenomenon is called

Correct Answer: (a) Reverberation.
Solution:
  • Reverberation is the persistence of sound after the sound source has been stopped. It results from a large number of reflected waves which can be perceived by the brain as a continuous sound.
    On the other hand, an echo occurs when a pulse of sound can be heard twice.

30. When light is scattered by a molecule and the frequency of the scattered light is changed, this phenomenon is called

Correct Answer: (b) Raman effect.
Solution:Ramen effect is the process of scattering of light particles by molecules of medium. The scattering occurs due to a change in the wavelength of light as it enters the medium.
When light is scattered by molecule and the frequency of the scattered light is changed, this phenomenon is explained by Raman effect. When light wave strike a medium, some of the energy of incident light may be increased or decreased the molecules of the medium, hence the scattered light may have frequency or wavelength increased or decreased.
Rayleigh scattering is a form of elastic scattering in which incident light and scattered light has same frequency.