Which one of the following is not an igneous rock?
- A.Granite
- B.Gneiss
- C.Pumice
- D.Basalt
Correct answer
Explanation
The correct answer is B, Gneiss. Gneiss is a metamorphic rock, formed when existing rocks are changed by great heat and pressure.
Igneous rocks form when molten magma or lava cools and hardens. Gneiss usually forms from granite or sedimentary rocks deep in the crust, and its minerals get arranged into light and dark bands, a texture called foliation. It is common in the ancient Peninsular shield of India.
A is wrong: granite is an intrusive igneous rock that cools slowly under the surface, so it has large crystals.
C is wrong: pumice is a volcanic igneous rock full of gas holes, so light that it can float on water.
D is wrong: basalt is an extrusive igneous rock from lava; the Deccan Traps are made of it, and it weathers into black soil.
Exam tip: metamorphic pairs = granite to gneiss, limestone to marble, sandstone to quartzite, shale to slate.
Practice Questions
View allWhich one of the following rivers is west-flowing?
- A.Godavari
- B.Periyar
- C.Tungabhadra
- D.Cauvery
Show answer
The Periyar rises in the Western Ghats of Kerala and flows west into the Arabian Sea. The Periyar is the longest river of Kerala.
Read the full explanation →Consider the following places of India :
1. Itanagar
2. Imphal
3. Agartala
4. Aizawl
Which one of the following is the correct chronological order of the above places in terms of sunrise time?
- A.3-2-1-4
- B.2-1-4-3
- C.1-4-3-2
- D.4-3-2-1
Show answer
The sun rises first in the place farthest east, so the order follows longitude: Imphal, Itanagar, Aizawl and then Agartala.
Read the full explanation →"Viticulture" is a common feature of which one of the following Australian cities ?
- A.Adelaide
- B.Darwin
- C.Hobart
- D.Brisbane
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Viticulture, the growing of grapes, is a hallmark of Adelaide, which is surrounded by Australia's best-known wine regions. Adelaide, the capital of South Australia, has a Mediterranean climate with hot, dry summers and mild, wet winters, the conditions grapevines like best.
Read the full explanation →Which of the following statements regarding Barchan is/are correct ?
1. It is a crescent shaped mound of sand, which is deposited by the wind blowing constantly from one direction in a desert.
2. The windward side has a convex steep slope with maximum height at the centre.
3. Two ends of Barchan are called horns and point opposite to the direction the wind blows.
Select the answer using the code given below :
- A.1 only
- B.1 and 2 only
- C.2 and 3 only
- D.1, 2 and 3
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A barchan is a crescent-shaped sand dune built by wind from one steady direction, but its windward slope is gentle and its horns point downwind.
Read the full explanation →Which part of India has the Kalakot tertiary coal field ?
- A.Brahmaputra river basin of Assam
- B.Damodar river basin of Jharkhand and West Bengal
- C.Himalayan mountain region
- D.Cardamom hills in Kerala
Show answer
Kalakot lies in the Reasi district of Jammu and Kashmir, in the foothills of the Himalaya. India's coal is of two ages.
Read the full explanation →