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. How the Cast Iron is different from Wrought Iron?
- Cast iron have higher carbon content than wrought iron
- Cast iron are more ductile compared to wrought iron
- Wrought iron is more stable, pure and stronger, compared to cast iron
Select the correct option from the codes given below:
[A] 3 Only
[B] 1 and 3 Only
[C] 2 and 3 Only
[D] 1,2 and 3
Show Answer
Correct Answer: B [ 1 and 3 Only]
Notes:
Second statement is wrong because wrought iron is more ductile compared to cast iron
3. As per the Mohs scale of mineral hardness, which of the following are soft metals?
- Gold
- Copper
- Diamond
- Thorium
Select the correct option from codes given below:
[A] 1 & 4 Only
[B] 1, 2 & 4 Only
[C] 2 & 4 Only
[D] 1, 2, 3 & 4
Show Answer
Correct Answer: B [ 1, 2 & 4 Only]
Notes:
As per the Mohs scale of mineral hardness, the soft metals are: Lead, gold, silver, tin, zinc, aluminium, thorium, copper, brass and bronze. Diamond is one of the hardest known metals on earth.
4. Flowers emit fragrance to ____:
[A] Drive away flies
[B] Purify air
[C] Attract insects
[D] All of the above
Show Answer
Correct Answer: C [Attract insects]
Notes:
Flowers emit fragrance to attract pollinators which are mainly insects. The fragrance plays a prominent role in the localization and selection of flowers by insects, especially moth-pollinated flowers, which are detected and visited at night. If they have become infested with herbivores like caterpillars, they attract beneficial insects like parasitic wasps with the help of scent signals from their leaves.
5. In winter, at the time of hibernation, Toads maintain breathing through ____:
[A] Lungs
[B] Skin
[C] Both by Skin and Lungs
[D] Buccal cavity
Show Answer
Correct Answer: B [Skin]
Notes:
During hibernation in winter, toads or frogs spend the time tucked away deep in the soil, in the mud underwater or hidden amidst foliage or rotting plants. Outside of times of hibernation, they usually take in oxygen via the air, employing their lungs. However, during hibernation, they receive their necessary oxygen through their permeable skin. This is referred to as cutaneous gas exchange.
6. 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.
7. Grey hair is caused due to
____:
[A] Aging of epidermal cells
[B] Death of dermal cells
[C] Loss of sebum in epidermal cells
[D] Loss of melanin in epidermal cells
Show Answer
Correct Answer: D [Loss of melanin in epidermal cells]
Notes:
The hair follicles have pigment cells that make melanin, a chemical that gives the hair its color. As one ages, these cells start to die. Without pigment, new hair strands grow in lighter and take on various shades of gray, silver, and eventually white.
8. Which of the following brings back deoxygenated blood from different parts of human body to heart?
[A] Veins
[B] Arteries
[C] Nerves
[D] Lungs
Show Answer
Correct Answer: A [Veins]
Notes:
Veins carry the deoxygenated blood from different parts of the body to the heart. There are two main veins that carry out this job. The superior vena cava carries deoxygenated blood from head, neck, thorax and hands to the right atrium of our heart. The inferior vena cava carries deoxygenated blood from legs, pelvic region and abdominal organs to the right atrium of our heart. Among the veins, only pulmonary vein carries oxygenated blood.
9. The special modified epidermal cells surrounding stomatal pore are called ____:
[A] Accessory cells
[B] Epithelial cells
[C] Guard cells
[D] Subsidiary cells
Show Answer
Correct Answer: C [Guard cells]
Notes:
The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the opening. Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gaseous exchange and rate of transpiration.
10. An example of false fruit is ___:
[A] Guava
[B] Mango
[C] Tomato
[D] Apple
Show Answer
Correct Answer: D [Apple]
Notes:
An accessory fruit (sometimes called false fruit, spurious fruit, pseudo-fruit, or pseudo-carp) is a fruit in which some of the flesh is derived not from the ovary but from some adjacent tissue exterior to the carpel. Examples of accessory tissue are the receptacle of strawberries, figs, or mulberries, and the calyx of Gaultheria procumbens or Syzygium jambos. Pomes, such as apples and pears, are also accessory fruits, with much of the fruit flesh derived from a hypanthium.
