Q: The heart covered by a membrane called

A: Myocardium.

B: Pericardium

C: Aorta

D: None of These



Correct Option: B  [ Pericardium ]

Remark:

Explanation: The heart is enclosed in a double-layered protective membrane called the pericardium. The outer fibrous layer protects the heart and anchors it within the chest cavity, while the inner serous layer secretes pericardial fluid that reduces friction during heartbeats. This fluid-filled sac ensures smooth and cushioned movement of the heart as it contracts and relaxes continuously.


Q: When a moving bus suddenly stops, passengers sitting inside leans forward. This is due to

A: Conservation of Mass

B: Inertia of rest

C: Inertia of Motion

D: None of these



Correct Option: C  [ Inertia of Motion ]

Remark:
Inertia of motion is defined as the property of a body to resist any change to its state of uniform motion.


Q: What is the S.I. unit of electric current?

A: Volt

B: Watt

C: Ampere

D: Ohm



Correct Option: C  [ Ampere ]

Remark:

Explanation: The S.I. unit of electric current is the Ampere (A). It is defined as the rate of flow of electric charge through a conductor. One ampere equals one coulomb of charge passing through a point in one second.


Q: Which of the following is not a property of acids ?

A: All acids have sour taste

B: All acids are corrosive in nature

C: For acidic solutions pH = <7

D: Acids turn red litmus to blue



Correct Option: D  [ Acids turn red litmus to blue ]

Remark:

Explanation: Acids do not turn red litmus to blue; instead, they turn blue litmus paper red. Acids are sour in taste, corrosive in nature, and have a pH value less than 7. Therefore, the statement that acids turn red litmus to blue is incorrect.


Q: Chiropterochory is a seed dispersal process through

A: Birds

B: Bats

C: Reptiles

D: Insects



Correct Option: B  [ Bats ]

Remark:

Explanation: Chiropterochory comes from the Greek words “chiroptera” (bats) and “chorein” (to spread). It refers to the dispersal of seeds by fruit bats or flying foxes, which feed on fruits and later excrete or drop the seeds away from the parent plant. This process helps in plant reproduction and maintaining forest diversity. Common examples include dispersal of seeds of guava, fig, and


Q: A fan produces a feeling of comfort during hot weather because:

A: fan supplies cool air

B: our body radiates more heat in air

C: conductivity of air increases

D: our perspiration evaporates rapidly



Correct Option: D  [ our perspiration evaporates rapidly ]

Remark:

Explanation: A fan provides a feeling of comfort during hot weather because it increases the rate of evaporation of sweat from our skin. As the perspiration evaporates rapidly due to moving air, it absorbs heat from the body, producing a cooling effect and making us feel more comfortable.


Q: Sericuluture is a rearing practice of :

A: Fishes

B: Silk worm

C: Honey bees

D: Earth worm



Correct Option: B  [ Silk worm ]

Remark:

Sericulture is the rearing and cultivation of silkworms for the production of silk. The process involves raising silkworms on mulberry leaves, harvesting their cocoons, and then extracting silk fibers from these cocoons. The most commonly used silkworm species is Bombyx mori. Sericulture is an important cottage industry in countries like India, China, and Japan.

Other options (for context)

  • Fishes: Their rearing is called Pisciculture.
  • Honey bees: Their rearing is called Apiculture.
  • Earth worms: Their cultivation for composting is called Vermiculture.


Q: Who invented the contact lens?

A: Enrico Fermi

B: Adolf Gaston Eugen Fick

C: Sandford Fleming

D: Benoit Fourneyron



Correct Option: B  [ Adolf Gaston Eugen Fick ]

Remark:

Adolf Gaston Eugen Fick, a German physiologist, invented the first successful contact lens in 1888. His design consisted of a glass lens that covered the entire eye, resting on the sclera (the white part of the eye). Though bulky and uncomfortable by today’s standards, it laid the foundation for modern soft and gas-permeable contact lenses used in vision correction and cosmetics.

Other options (for context)

  • Enrico Fermi: Known for his work in nuclear physics and development of the first nuclear reactor.
  • Sandford Fleming: Introduced the concept of standard time zones.
  • Benoit Fourneyron: Invented the water turbine, not related to optics or vision correction.


Q: Which of the following colours is not seen in a rainbow ?

A: Yellow

B: Green

C: Red

D: Brown



Correct Option: D  [ Brown ]

Remark:

Brown is not seen in a rainbow. A natural rainbow displays seven distinct colours — Violet, Indigo, Blue, Green, Yellow, Orange, and Red (VIBGYOR). These colours appear due to the dispersion of sunlight by water droplets in the atmosphere, but brown is not part of the visible spectrum formed by dispersion.

  • Yellow, Green, Red: All are part of the seven colours of the rainbow.


Q: The mountaineers carry oxygen with them because:

A: at an altitude of more than 5 km there is no air

B: the amount of air available to a person onmountain is lesser than that available on the ground

C: the temperature of air is lesser than that onthe ground.

D: The pressure of air is higher than that on theground.



Correct Option: B  [ the amount of air available to a person onmountain is lesser than that available on theground ]

Remark:

Mountaineers carry oxygen cylinders because the amount of air (and oxygen) available at high altitudes is much less than that at ground level. As altitude increases, air pressure and oxygen concentration decrease, making breathing difficult and leading to altitude sickness. Supplemental oxygen helps them breathe properly and maintain body function.

  • No air above 5 km: Incorrect — air exists but is thinner.
  • Lower temperature: True but not the reason for carrying oxygen.
  • Higher air pressure: Incorrect — pressure decreases with height.
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