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. What are the products of the reaction when metal carbonate reacts with an acid?
[A] Salt and Hydrogen
[B] Carbon dioxide
[C] Salt, Carbon dioxide and water
[D] Salt, Carbon dioxide and Hydrogen
Show Answer
Correct Answer: C [Salt, Carbon dioxide and water]
Notes:
All metal carbonates and hydrogen carbonates react with acids to give a corresponding salt, carbon dioxide and water. Limestone, chalk and marble are different forms of calcium carbonate.
2. Which of the following elements is present in heavy water?
[A] Heavy Oxygen
[B] Heavy Hydrogen
[C] Heavy Chlorine
[D] Heavy Nitrogen
Show Answer
Correct Answer: B [Heavy Hydrogen ]
Notes:
Heavy water is water that contains heavy hydrogen or deuterium. Deuterium differs from the hydrogen usually found in water, protium, in that each atom of deuterium contains a proton and a neutron. Heavy water may be deuterium oxide, D2O or it may be deuterium protium oxide, DHO.
3. Which among the following metals is the hardest metal?
[A] Platinum
[B] Gold
[C] Iron
[D] Tungsten
Show Answer
Correct Answer: D [Tungsten]
Notes:
Tungsten has the highest tensile strength of any natural metal, with an ultimate strength of 1510 megapascals. Tungsten has the highest melting point (3422 °C, 6192 °F), lowest vapor pressure (at temperatures above 1650 °C, 3000 °F).
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. Which of the following gases helps in bread/cake fermentation so as to make it soft and spongy?
[A] Carbon Monoxide
[B] Hydrogen
[C] Carbon Dioxide
[D] Oxygen
Show Answer
Correct Answer: C [Carbon Dioxide]
Notes:
Fermentation is an anaerobic chemical process that breaks down glucose molecules. In baking, yeast consumes sugar and converts it into carbon dioxide and alcohol, making the dough rise. This gas gets trapped in the strands of gluten, resulting in air pockets that cause the dough to rise and form the characteristic spongy texture of bread and cakes. Further, the creation of lactic and acetic acids during fermentation augments this dough handling process, improves flavor, enhances the texture, and extends the shelf-life of the baked products.
6. The ____ is the stem-like part of the leaf that joins the blade to the stem, is known as:
[A] Vein
[B] Petiole
[C] Stipules
[D] Midrib
Show Answer
Correct Answer: B [Petiole]
Notes:
The petiole is the stalk-like structure which connects the leaf blade to the stem. The petiole has tiny tubes, that connect the veins on the leaf blade to the stem. Few of these enable water transport to the leaf while the other carry food away from the leaf to other parts of the plant.
7. Which of the following protein is found in nails?
[A] Keratin
[B] Histone
[C] Actin
[D] Elastin
Show Answer
Correct Answer: A [Keratin]
Notes:
Keratin is a family of fibrous structural proteins that is the key structural component of hair and nails. It is also the key structural material making up the outer layer of human skin. Besides, it provides the necessary strength and toughness for masticatory organs, such as the tongue.
8. Symbiotic Bacteria responsible for the fixation of atmospheric nitrogen are present in ____:
[A] Peas
[B] Oats
[C] Corn
[D] Wheat
Show Answer
Correct Answer: A [Peas]
Notes:
Nitrogen-fixing bacteria are microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen. Rhizobium is one such bacteria that is associated with leguminous plants (e.g., various members of the pea family). It invades the root hairs of host plants and convert free nitrogen to ammonia, which the host plant utilizes for its development.
9. The release of which of the following into ponds and wells helps in controlling mosquitoes?
[A] Snail
[B] Crab
[C] Dogfish
[D] Gambusia fish
Show Answer
Correct Answer: D [Gambusia fish]
Notes:
The Gambusia fish, also known as larvivorous stagnant water fish. It feeds on the larvae of mosquitoes. So it helps in controlling their population. It is also called ‘mosquito fish’ and is being used as a biological control measure. Hence, a check on malaria and other vector borne diseases like even dengue.
10. What are female gametes called as?
[A] Zygote
[B] Sperms
[C] Embryo
[D] Ova
Show Answer
Correct Answer: D [Ova]
Notes:
Female gametes are also called eggs or ova. They are created during the cellular reproduction process known as meiosis. The resulting gamete cell is a haploid cell. When the two haploid cells, the egg and sperm, fuse together during fertilization, the result is a diploid cell called a zygote.