General Science Questions (MCQs) for Competitive Examinations
General Science Multiple choice questions for GK paper in SSC, NDA, CDS, UPSC, UPPSC and State PSC Examinations. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
1. Which iron ore contains the highest percentage of iron content?
[A] Hematite
[B] Siderite
[C] Magnetite
[D] Limonite
Show Answer
Correct Answer: C [Magnetite]
Notes:
Magnetite (Fe3O4) typically contains about 70% iron by weight. It is black in color and strongly magnetic. Hematite (Fe2O3) contains about 60–70% iron. Limonite contains 35–50% iron. Siderite (FeCO3) contains about 48% iron. Magnetite is widely mined due to its high iron concentration compared to other ores.
2. Which among the following is known as White Vitriol?
[A] Zinc Sulphate
[B] Zinc Chloride
[C] Zinc Phosphate
[D] Zinc oxide
Show Answer
Correct Answer: A [Zinc Sulphate]
Notes:
Zinc sulfate is the inorganic compound with the formula ZnSO4 and historically known as “white vitriol” Zinc sulfate is an inorganic compound and dietary supplement.
3. Which of the following are the limitations of Bohr’s model of atom?
[A] it cannot explain spectrum of atoms containing more than one electron
[B] it cannot explain the Zeeman effect
[C] it cannot explain the Stark effect
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Bohr’s model of atom cannot explain spectrum of atoms containing more than one electron. Also, it cannot explain the Zeeman effect i.e. splitting of spectral line in presence of magnetic field. It also fails to explain Stark effect i.e. splitting of spectral line in presence of electric field.
4. What is the common name of ‘Ca(ClO)2’?
[A] Baking Soda
[B] Bleaching Powder
[C] Washing Soda
[D] Baking Powder
Show Answer
Correct Answer: B [Bleaching Powder]
Notes:
Calcium hypochlorite is an inorganic compound with formula Ca(ClO)2. It is the main active ingredient of commercial products called bleaching powder, chlorine powder, or chlorinated lime, used for water treatment and as a bleaching agents.
5. In the grass lands, trees do not replace the grasses as a part of an ecological succession because of ____:
[A] Limited sun light and paucity of nutrients
[B] Insect and fungi
[C] Water limits and fire
[D] None of the above
Show Answer
Correct Answer: C [Water limits and fire]
Notes:
Ecological succession is unidirectional progressive process of development in an ecosystem or biome. Grass ecosystems are an early stage of succession in regions where the mature ecosystems are forests. However, grass ecosystems are climax ecosystems in grassland regions, where there is not enough rainfall to support a forest. Due to limiting factors such as water scarcity and forest fire, a grassland ecosystem changes to a desert ecosystem. The ecological succession of grassland is desert.
6. What is thick vein present in the middle of the leaf called?
[A] Leaf venation
[B] Parallel venation
[C] Midrib
[D] Reticulate
Show Answer
Correct Answer: C [Midrib]
Notes:
A thick vein seen in the middle of the leaf is called the midrib. Pinnately veined leaves have one large central vein, called the midrib, which extends from the base of the blade to its tip. Other large veins branch off on each side of the midrib. The leaves of beech, birch, and elm trees have such a vein pattern.
7. Which one of the following is commonly known as Pond Silk?
[A] Yeast
[B] Rhizopus
[C] Ulothrix
[D] Spirogyra
Show Answer
Correct Answer: D [Spirogyra]
Notes:
Pond silk is the common name of Spirogyra (algae) because it is very slimy in shape. It is also known as pond silk, water silk, pond scum or mermaid’s trees because of its bright green silky appearance. Its filaments shine like silk due to the presence of mucilage and spiral shaped chloroplast.
8. Uric acid is the chief nitrogenous wastes in ____:
[A] Frogs
[B] Birds
[C] Fishes
[D] Mankind
Show Answer
Correct Answer: B [Birds]
Notes:
Land snails, insects, birds, and some reptiles excrete uric acid as the major nitrogenous waste. The white, crystalline substance seen in a typical bird or lizard “poop” is actually urine: a little pool of uric acid crystals in a very small amount of water.
9. To digest protein which of the enzyme is present in pancreatic juice?
[A] Pepsin
[B] Upes
[C] Trypsin
[D] Amaylase
Show Answer
Correct Answer: C [Trypsin]
Notes:
Trypsin is an enzyme that helps us digest protein. In the small intestine, trypsin breaks down proteins, continuing the process of digestion that began in the stomach. It may also be referred to as a proteolytic enzyme, or proteinase. Trypsin is produced by the pancreas in an inactive form called trypsinogen. The trypsinogen enters the small intestine through the common bile duct and is converted to active trypsin.
10. The most serious air pollutant causing health hazard is ____:
[A] Ozone
[B] Sulphur dioxide
[C] Nitrogen oxide
[D] Carbon monoxide
Show Answer
Correct Answer: B [Sulphur dioxide]
Notes:
Sulphur dioxide (SO2) is considered as the most serious single air pollutant causing health hazard, obstructing breathing. It always leads to airways inflammation, eye irritation, psychic alterations, pulmonary oedema, heart failure and circulatory collapse. It is also responsible for acid rain.