Science GK Quiz for Competitive Exams

Science GK Quiz for Competitive Exams
Q :  

Identify an example of decomposers found at the bottom of a pond.

(A) Zooplankton

(B) Jellyfishes

(C) Flagellates

(D) Phytoplankton


Correct Answer : C
Explanation :

The sole decomposers in the pond ecosystem are earthworms and fungi. In pond water, earthworms and fungi can develop and feed on dead and decaying species.


Q :  

Which of the following is commonly known as Quicklime?

(A) CaO

(B) Ca(OH)2

(C) CaCO3

(D) CaCl2.6H2OD


Correct Answer : D
Explanation :

Calcium oxide, commonly known as quicklime or burned lime, is a chemical substance with the chemical formula CaO.


Q :  

Which of the following is an organic compound with the formula CH3OC6H5 used as a perfume, fragrance and solvent?

(A) Anisole

(B) Toluene

(C) Acetophenone

(D) Aniline


Correct Answer : A
Explanation :

Anisole, or methoxybenzene, is an organic compound with the formula CH 3OC 65. It is a colorless liquid with a smell reminiscent of anise seed, and in fact many of its derivatives are found in natural and artificial fragrances.


Q :  

Which layer of the atmosphere helps in radio transmission?

(A) Exosphere

(B) Thermosphere

(C) Mesosphere

(D) Stratosphere


Correct Answer : B
Explanation :

The thermosphere layer of the Atmosphere helps in Radio Transmission. It is located above the mesosphere and below the exosphere. In the thermosphere, the temperature rises rapidly with increasing height. The ionosphere is a part of this layer.


Q :  

In 1955, which synthetic element is provisionally named Mendelevium in honour of Dmitri Mendeleev, who created one of the first periodic tables?

(A) Element 90

(B) Element 101

(C) Element 103

(D) Element 106


Correct Answer : B
Explanation :

The correct answer is Element 101. Dmitri Ivanovich Mendeleev was a Russian chemist and inventor. He is best remembered for formulating the Periodic Law and creating a farsighted version of the periodic table of elements.


Q :  

According to Mendeleev's periodic table, what was the atomic mass of Eka-aluminium which was later replaced by Gallium?

(A) 95

(B) 83

(C) 68

(D) 50


Correct Answer : C
Explanation :

Mendeleev's periodic table Mendeleev published the periodic table in 1869 but not all the elements were discovered by that time, so he left some spaces under Aluminium and Silicon. He examined the relationship between atomic masses and the physical and chemical properties of elements. While preparing the periodic table there were a few instances where he had to place elements with a slightly greater atomic mass before an element with a slightly lower atomic mass as he wanted to place elements with similar chemical properties together. Periodic law states that "properties of elements are periodic function of their atomic masses.


Q :  

The common name of the compound CaOCl2 is ______.

(A) Bleaching powder

(B) Washing Soda

(C) Baking Soda

(D) Gypsum


Correct Answer : A
Explanation :

Calcium hypochlorite is known as bleaching powder.


Q :  

Which of the following can be used to complete an electric circuit if one runs out of connecting wire?

(A) A paper strip

(B) A rubber belt

(C) A wooden stick

(D) A blade


Correct Answer : D
Explanation :

Through the conductor, electric current can flow easily or electrons can move freely from one atom to another. So, a blade can be used to complete an electric circuit if one runs out of connecting wire.


Q :  

Recently researchers from which state have identified two new species of fungus belonging to the genus Ganoderma?

(A) Tamil Nadu

(B) Kerala

(C) Karnataka

(D) Assam


Correct Answer : B
Explanation :

Researchers from Kerala have identified two new species of fungi from the genus Ganoderma that are associated with coconut stem rot. They have also genotyped the two fungi species, named Ganoderma keralense and G.


Q :  

Which of the following statements is/are correct?

A. Tron can replace zine from zinc sulphate solution.

B. Zinc can replace copper from solution. copper sulphate

C. Copper can replace Iron from Iron sulphate solution.

(A) Only A

(B) Only B

(C) A and B

(D) B and C


Correct Answer : A
Explanation :

Zinc is used in alloys with copper to create a harder metal known as brass. If Zinc metal is dipped in the Copper sulphate solution the reaction will take place because zinc is more reactive than copper and it will displace the copper from copper sulphate solution to form Copper and Zinc sulphate.


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    Rajesh Bhatia

    A Writer, Teacher and GK Expert. I am an M.A. & M.Ed. in English Literature and Political Science. I am highly keen and passionate about reading Indian History. Also, I like to mentor students about how to prepare for a competitive examination. Share your concerns with me by comment box. Also, you can ask anything at linkedin.com/in/rajesh-bhatia-7395a015b/.

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