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 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).
3. Who discovered electron?
[A] John Dalton
[B] James Chadwik
[C] Ernest Rutherford
[D] J J Thomson
Show Answer
Correct Answer: D [J J Thomson]
Notes:
Electron was discovered by an Irish scientist J J Thomson and electron is the first subatomic particle to be discovered. J J Thomson is notable for proposing the water melon model which is also called as plum pudding model.
4. Carbon monoxide poisoning can be cured by
____:
[A] Drinking lemon-water
[B] Eating butter
[C] Exposing the affected person to fresh oxygen
[D] Consuming multi-vitamin tablet
Show Answer
Correct Answer: C [Exposing the affected person to fresh oxygen]
Notes:
Carbon monoxide poisoning can be cured by exposing the affected person to fresh oxygen. It is because CO posoning leads to oxygen starvation of body cells. This therapy involves breathing pure oxygen in a chamber in which the air pressure is about two to three times higher than normal. This speeds the replacement of carbon monoxide with oxygen in your blood. Hyperbaric oxygen therapy may be used in cases of severe carbon monoxide poisoning.
5. 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.
6. _____ is the study of the microanatomy of cells, tissues and organs as seen through a microscope:
[A] Entomology
[B] Paleontology
[C] Histology
[D] Lchthyology
Show Answer
Correct Answer: C [Histology]
Notes:
Histology is the study of the micro anatomy of cells, tissues, and organs as seen through a microscope. It examines the correlation between structure and fun-ction.Histology is the micro-scopic counterpart to gross anatomy which looks at larger structures visible without a microscope.
7. What is the basis of classifying various plant tissues as meristematic tissue and permanent tissue?
[A] Size
[B] Dividing capacity
[C] Location
[D] None of the above
Show Answer
Correct Answer: B [Dividing capacity]
Notes:
Based on the dividing capacity of the tissues, various plant tissues can be classified as growing or meristematic tissue and permanent tissue. Meristem is a type of tissue system in plants, composed of a mass of undifferentiated cells and their primary function is to take part in the growth of plants. Permanent tissues are differentiated tissues doing specific functions such as conduction, providing mechanical support or carrying out photosynthesis etc.
8. Which of the following is/are agent(s) of infection?
[A] Physical contact
[B] Water
[C] Vectors
[D] All of the above
Show Answer
Correct Answer: D [All of the above ]
Notes:
Infection is the invasion of an organism’s body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce. Infectious diseases can be spread from one person to another, for example through contact with bodily fluids, by aerosols (through coughing and sneezing), or via a vector, for example a mosquito.
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. In the context of agriculture, the term barani refers to ____:
[A] Rain-fed farming
[B] Irrigated farming
[C] Mixed farming
[D] Dry farming
Show Answer
Correct Answer: A [Rain-fed farming]
Notes:
Barani area are traditionally rain-fed areas. These are any low rain area where the rain-fed dry farming is practiced. Bagar tract, the dry sandy tract of land on the border of Rajasthan state adjoining the states of Haryana and Punjab, is an example of Barani land.
