Q: Who discovered electromagnetic nature of light?

A: Young

B: Snell

C: Newton

D: Maxwell



Correct Option: D  [ Maxwell ]

Remark:


Q: The gas used for artificial ripening of green fruit is:

A: Ethylene

B: Ethane

C: Carbon dioxide

D: None of these



Correct Option: A  [ Ethylene ]

Remark:

Explanation: The gas used for artificial ripening of green fruits is ethylene (C₂H₄). Ethylene is a natural plant hormone that regulates fruit ripening by stimulating the conversion of starches into sugars, making the fruit softer and sweeter. In artificial ripening, ethylene gas is introduced in controlled amounts to uniformly ripen fruits such as bananas, mangoes, and tomatoes. However, the use of harmful chemicals like calcium carbide for ripening is banned because it produces toxic substances like acetylene.


Q: Green leafy vegetable are rich source of :

A: Citric acid

B: Malic acid

C: Folic acid

D: none of these



Correct Option: C  [ Folic acid ]

Remark:

Green leafy vegetables are a rich source of Folic Acid (Vitamin B₉). Folic acid is essential for the formation of red blood cells, DNA synthesis, and proper cell growth. It is particularly important for pregnant women, as it helps prevent neural tube defects in the developing fetus. Vegetables like spinach, kale, lettuce, and fenugreek leaves are excellent sources of folic acid.

Other options (for context)

  • Citric acid: Found mainly in citrus fruits like oranges and lemons.
  • Malic acid: Commonly present in apples and other fruits, not in leafy greens.
  • None of these: Incorrect — folic acid is the correct nutrient associated with green leafy vegetables.


Q: What is the temperature when density of water is the highest

A: 5 degree Celsius

B: 6 degree Celsius

C: 4 degree Celsius

D: 3 degree Celsius



Correct Option: C  [ 4 Degree Celsius ]

Remark:

Explanation: Water shows an unusual property known as anomalous expansion. Its density is maximum at 4°C. When cooled from higher temperatures, water contracts till 4°C, becoming denser. Below 4°C, it expands instead of contracting, so its density decreases. This property allows ice to float and prevents water bodies from freezing solid, protecting aquatic life during winters.


Q: The weight of a body at the centre of the earth is:

A: zero

B: infinite

C: same as at other places

D: none of these



Correct Option: A  [ zero ]

Remark:

Explanation: The weight of a body at the centre of the Earth is zero because the gravitational forces from all directions cancel each other out. Although the body still has mass, it experiences no gravitational pull, resulting in zero weight.


Q: Norman E. Borlaug is associated with

A: Green Revolution

B: White Revolution

C: Pink Revolution

D: Blue Revolution



Correct Option: A  [ Green Revolution ]

Remark:
Norman E. Borlaug was awarded the Nobel Peace Prize in 1970 in recognition of his contributions to global food production.


Q: 'Mirage' is an example of:

A: refraction of light only

B: total internal reflection of light only

C: refraction and total internal reflection of light

D: dispersion of light only



Correct Option: C  [ refraction and total internal reflection of light ]

Remark:

Explanation: A mirage is an optical illusion caused by both refraction and total internal reflection of light. It occurs when light rays bend due to temperature variations in air layers near the ground, creating the illusion of water or a reflected image on hot surfaces like roads or deserts.


Q: Full form of "GPS" is

A: Geographic Pointing System

B: Global Positioning System

C: Geographic Photo Sensor

D: Global Polar Synchronization



Correct Option: B  [ Global Positioning System ]

Remark:

Explanation: The full form of GPS is Global Positioning System. It is a satellite-based navigation system that provides accurate information about the location, speed, and time anywhere on Earth. Developed by the U.S. Department of Defense, GPS uses a network of at least 24 satellites orbiting the Earth. It is widely used in navigation, mapping, military operations, aviation, and smartphone tracking applications.


Q: Which of the following is not an element ?

A: Oxygen

B: Nitrogen

C: Hydrogen

D: Marble



Correct Option: D  [ Marble ]

Remark:

Marble is not an element; it is a metamorphic rock composed primarily of calcium carbonate (CaCO₃). It forms when limestone is subjected to high pressure and temperature, causing recrystallization. Being a compound and mixture of minerals, marble does not consist of a single type of atom, unlike elements.

Other options (for context)

  • Oxygen (O₂): A chemical element essential for respiration and combustion.
  • Nitrogen (N₂): A chemical element that makes up about 78% of Earth’s atmosphere.
  • Hydrogen (H₂): The lightest chemical element and the main component of stars.


Q: One (1) molecule of CFC deplete __________ molecule of Ozone in the Ozonosphere.

A: 1,00,000

B: 10,000

C: 10,00,000

D: No one of the above



Correct Option: A  [ 1,00,000 ]

Remark:

One molecule of a Chlorofluorocarbon (CFC) can destroy up to 1,00,000 molecules of ozone (O₃) in the ozone layer. When CFCs reach the stratosphere, they are broken down by ultraviolet (UV) radiation, releasing chlorine atoms. Each chlorine atom acts as a catalyst in the breakdown of ozone molecules, significantly depleting the protective ozone layer that shields Earth from harmful UV rays.

Other options (for context)

  • 10,000: Underestimates the destructive potential of a single CFC molecule.
  • 10,00,000: Overestimates the number of ozone molecules destroyed.
  • No one of the above: Incorrect — the correct answer is 1,00,000 molecules of ozone.
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