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 of the following is correct about effective nuclear charge experienced by the orbital?
[A] it increases with increase of azimuthal quantum number
[B] it increases with increase of magnetic quantum number
[C] it decreases with increase of azimuthal quantum number
[D] It is same everywhere
Show Answer
Correct Answer: C [it decreases with increase of azimuthal quantum number]
Notes:
Because of the screening effect, the net positive charge experienced by the electron from the nucleus is lowered and is known as effective nuclear charge. Effective nuclear charge experienced by the orbital decreases with increase of azimuthal quantum number(l).
2. 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.
3. 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.
4. 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.
5. Which word is common in the botanical names of trees like Ashoka, Tamarind or Coral?
[A] Terminalia
[B] Indica
[C] Salix
[D] Acacia
Show Answer
Correct Answer: B [Indica]
Notes:
Tamarind tree (Tamarindus indica), Ashoka tree (Saraca Indica), Indian Coral tree (Erythrina Indica) have ‘Indica’ common in their botanical names. In biology/taxonomy, if a species originates in India, its scientific name sometimes includes “Indica”.
6. Seed dormancy is regulated by ____:
[A] Abscisic acid
[B] Indole acetic acid
[C] Ethylene
[D] Gibberellic acid
Show Answer
Correct Answer: A [Abscisic acid]
Notes:
The transition from dormancy to germination in seeds is a key physiological process during the lifecycle of plants. Abscisic acid (ABA) is the sole plant hormone known to maintain seed dormancy. It acts through a gene expression network involving the transcription factor Abscisic Acid Insensitive 3 (ABI3).
7. The pigment that gives human skin, hair and eyes their colour is called ____:
[A] Quinacridone
[B] Alizarin
[C] Melanin
[D] Phthalocyanine
Show Answer
Correct Answer: C [Melanin ]
Notes:
The pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes. Everyone has the same number of melanocytes, but some people make more melanin than others.
8. Cuscuta is a ____:
[A] Complete stem parasite
[B] Partial root parasite
[C] Partial stem parasite
[D] Complete root parasite
Show Answer
Correct Answer: A [Complete stem parasite]
Notes:
Cuscuta (Dodder) is a genus of about 100-170 species of yellow, orange or red (rarely green) parasitic plants. Dodders are supremely adapted for a life of plunder and pillage. Reduced in form to scrambling and twining threads, they appear to be completely leafless, although closer inspection reveals tiny scale leaves pressed close to the stems. So, it is a stem parasite.
9. Preserved traces of living organisms retained in the form of impressions of the body parts in the soil are called ____:
[A] Specimen
[B] Phylogeny
[C] Fossils
[D] Antique
Show Answer
Correct Answer: C [Fossils]
Notes:
A fossil is the naturally preserved remains or traces of organisms that lived in the geologic past. There are two main types of fossils; body and trace. Body fossils include the remains of organisms that were once living, and trace fossils are the signs that organisms were present (i.e. footprints, tracks, trails, and burrows).
10. The ____ helps in equalising the pressure on either sides of the eardrum:
[A] Malleus
[B] Incus
[C] Cochlear nerve
[D] Eustachian tube
Show Answer
Correct Answer: D [Eustachian tube]
Notes:
The eustachian tube is a canal that connects the middle ear to the nasopharynx. It controls the pressure within the middle ear, making it equal with the air pressure outside the body. The cochlear nerve is also known as the acoustic nerve. It transfers auditory information from the cochlea (auditory area of the inner ear) to the brain. The malleus transmits the sound vibrations from the eardrum to the incus, and then to the stapes.
