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: How much time the light from Sun takes to reach the Earth ?

A: 2 minutes

B: 4 minutes

C: 8 minutes

D: 12 minutes



Correct Option: C  [ 8 minutes ]

Remark:

Explanation: Light from the Sun takes approximately 8 minutes and 20 seconds to reach the Earth. The average distance between the Earth and the Sun is about 149.6 million kilometers (1 Astronomical Unit). Since light travels at a speed of 3 × 108 meters per second in a vacuum, it covers this distance in roughly eight minutes. This means that when we see sunlight, we are actually seeing it as it was about eight minutes earlier.


Q: Glaciers always melt first at the:

A: top surface

B: sides

C: bottom

D: middle surface



Correct Option: C  [ bottom ]

Remark:

Glaciers usually melt first at the bottom. The pressure at the base of a glacier is very high, which lowers the melting point of ice — a phenomenon known as pressure melting. Additionally, heat from the Earth’s crust and friction caused by glacier movement also contribute to faster melting at the base.

  • Top surface: Exposed to air but melts slower due to lower pressure.
  • Sides and middle surface: Experience less pressure and friction, so melting is slower.


Q: Insulin is secreted by :

A: Pancreas

B: Liver

C: Gall Bladder

D: Kidney



Correct Option: A  [ Pancreas ]

Remark:

Explanation: Insulin is a hormone secreted by the beta (β) cells of the Islets of Langerhans in the pancreas. Its main function is to regulate the blood glucose level by promoting the uptake of glucose into cells and converting excess glucose into glycogen in the liver and muscles. A deficiency or lack of insulin causes diabetes mellitus, leading to high blood sugar levels. The pancreas also secretes glucagon, which performs the opposite function by increasing blood glucose levels.


Q: Nitrogen is an essential constituent of all:

A: Carbohydrates

B: Fats

C: Proteins

D: Vitamins



Correct Option: C  [ Proteins ]

Remark:

Explanation: Proteins are complex organic compounds composed of smaller units called amino acids. Each amino acid contains an amino group (–NH₂), which contributes nitrogen to the molecular structure. This makes nitrogen an essential element in all proteins. Carbohydrates and fats lack nitrogen, while only some vitamins contain it.


Q: Neutron was discovered by:

A: J. Chadwick

B: J. J. Thomson

C: Rutherford

D: Neil Bohr



Correct Option: A  [ J. Chadwick ]

Remark:

Explanation: Neutron was discovered by James Chadwick in 1932. He identified the neutron as a neutral subatomic particle present in the nucleus of an atom, having a mass nearly equal to that of a proton but no electrical charge.


Q: Fruits of this plant are found underground

A: Potato

B: Carrot

C: Groundnut

D: Onion



Correct Option: C  [ Groundnut ]

Remark:

Explanation: Groundnut (Arachis hypogaea) is a leguminous plant that exhibits geocarpy — after fertilization a downward-growing peg pushes the fertilized ovary into the soil and the pod (the fruit) matures below ground. Potato, carrot and onion are underground plant parts but are respectively a tuber (stem), root and bulb — not fruits.


Q: Persistence of vision is the principle behind:

A: Camera

B: Binocular

C: Cinema

D: Periscope



Correct Option: C  [ Cinema ]

Remark:


Q: Pure gold is of

A: 24 Carat

B: 18 Carat

C: 22 Carat

D: None of these



Correct Option: A  [ 24 Carat ]

Remark:
A "carat" is a unit of measurement used to express the weight of gemstones, particularly diamonds and gold etc.


Q: The red planet is

A: Venus

B: Saturn

C: Mars

D: Neptune



Correct Option: C  [ Mars ]

Remark:

Explanation: Mars is known as the Red Planet because its surface contains a large amount of iron oxide (rust), which gives it a reddish appearance. It is the fourth planet from the Sun and has two moons — Phobos and Deimos.

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