Q: Which kind of lens is used in microscope ?

A: Convex

B: Concave

C: Biconvex and concave

D: Biconcave



Correct Option: A  [ Convex ]

Remark:

Explanation: A microscope uses a system of convex lenses to magnify very small objects. Convex lenses, also known as converging lenses, bend light rays inward to a focal point, creating an enlarged and clear image of the specimen. A compound microscope typically contains two sets of convex lenses — the objective lens (near the specimen) and the eyepiece lens (near the observer’s eye). The objective lens forms a real, inverted, and magnified image, which is then further magnified by the eyepiece to produce a large virtual image.


Q: Xylem helps in transportation of which of the following?

A: food

B: water

C: nutrient

D: both food and water



Correct Option: B  [ water ]

Remark:

Xylem is a type of vascular tissue in plants responsible for the transportation of water and dissolved minerals from the roots to the stems and leaves. The upward movement of water through xylem vessels occurs due to processes like transpiration pull, root pressure, and capillary action. Xylem also provides mechanical support to the plant.

Other options (for context)

  • Food: Transported by phloem, not xylem.
  • Nutrient: Minerals are carried along with water but the primary function of xylem is water transport.
  • Both food and water: Incorrect — only phloem transports food; xylem transports water.


Q: What makes a lemon sour?

A: Tartaric acid

B: Oxalic acid

C: Citric acid

D: Hydrochloric acid



Correct Option: C  [ Citric acid ]

Remark:

Explanation: The sour taste of a lemon is due to the presence of citric acid. Citric acid is a weak organic acid found naturally in citrus fruits such as lemons, oranges, and limes. It gives them their characteristic tangy flavor and also acts as a natural preservative.


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: One kilometre is equal to how many miles?

A: 0.84

B: 0.5

C: 1.6

D: 0.62



Correct Option: D  [ 0.62 ]

Remark:


Q: Which wave is being used by common TV remote control ?

A: Radio waves

B: Micro waves

C: Infrared waves

D: Ultrasonic waves



Correct Option: C  [ Infrared waves ]

Remark:


Q: 'Shock –absorbers' are usually made of steel as it:

A: is not brittle

B: has lower elasticity

C: has higher elasticity

D: has no ductile property



Correct Option: C  [ has higher elasticity ]

Remark:


Q: In which year was the "@" chosen for its use in e-mail addresses?

A: 1972

B: 1976

C: 1980

D: 1984



Correct Option: A  [ 1972 ]

Remark:


Q: Which acid is released when an Ant bites?

A: Hydrochloric Acid

B: Formic Acid

C: Acetic Acid

D: Phosphoric Acid



Correct Option: B  [ Formic Acid ]

Remark:

When an ant bites, it releases formic acid (HCOOH) into the skin. This acid causes a sharp burning sensation, redness, and irritation at the site of the bite. The name “formic” comes from the Latin word “formica”, meaning ant, as the acid was first extracted from ants. The pain can be neutralized by applying a mild base like baking soda (sodium bicarbonate).

Other options (for context)

  • Hydrochloric Acid: Found in the human stomach, aids digestion.
  • Acetic Acid: Main component of vinegar, not involved in ant bites.
  • Phosphoric Acid: Used in fertilizers and soft drinks, not produced by ants.


Q: Ozone layer is situated in the upper regions of

A: Troposphere

B: Stratosphere

C: Magnetosphere

D: Mesosphere



Correct Option: B  [ Stratosphere ]

Remark:

Explanation: The ozone layer is located in the stratosphere, which is the second layer of the Earth’s atmosphere, lying above the troposphere and extending from about 10 km to 50 km above the Earth’s surface. The ozone layer contains a high concentration of ozone gas (O₃), which absorbs most of the Sun’s harmful ultraviolet (UV) radiation. This protective shield prevents genetic damage, skin cancer, and other harmful effects on living organisms.

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