Consider the following statements regarding the nature of rocks : I. Rocks are aggregates of one or more minerals. II. Granite is softer than soapstone. III. Gabbro is black and quartzite can be milky white. IV. Sedimentary rocks are related to foliation. Which of the statements given above are not correct ?
- A.I and II
- B.I and III
- C.II and IV
- D.II and III
Correct answer
Explanation
The correct answer is C, II and IV. Granite is far harder than soapstone, and foliation is a feature of metamorphic rocks, not sedimentary ones, so these two statements are wrong.
A rock is a natural aggregate of one or more minerals, so statement I is correct. Soapstone, made mostly of talc, is so soft it can be scratched with a fingernail, while granite, rich in quartz and feldspar, is one of the hardest common rocks; statement II reverses this. Gabbro, a coarse igneous rock rich in dark minerals, is black or dark grey, and quartzite, formed from sandstone, is often white or milky, so statement III is correct. Foliation, the parallel banding of minerals produced by heat and pressure, is seen in metamorphic rocks such as slate, schist and gneiss; sedimentary rocks show layers called strata instead.
A, B and D are wrong because each includes statement I or III, which are correct, as an incorrect statement.
Exam tip: foliation, metamorphic; strata and fossils, sedimentary; talc, softest mineral on the Mohs scale.
Practice Questions
View allWhich one of the following States is not prominent for plantation agriculture ?
- A.Rajasthan
- B.Assam
- C.Nagaland
- D.Kerala
Show answer
Plantation agriculture means growing a single cash crop such as tea, coffee, rubber or spices on large estates, with heavy capital, hired labour and processing on the spot.
Read the full explanation →How is strong pressure gradient represented on a weather map?
- A.Closely spaced isobars
- B.Widely spaced isobars
- C.Closely spaced isobars at the periphery
- D.A set of two widely spaced isobars followed by two closely spaced isobars
Show answer
Isobars are lines on a weather map joining places that have the same atmospheric pressure, reduced to sea level. The pressure gradient is the rate at which pressure changes over a horizontal distance.
Read the full explanation →Which one of the following pairs of lakes is connected by Soo Canal?
- A.Superior and Michigan
- B.Superior and Huron
- C.Huron and Ontario
- D.Huron and Erie
Show answer
The Soo Locks, or Sault Ste. Marie canals, carry ships around the rapids of the St. Marys River, which drains Lake Superior into Lake Huron.
Read the full explanation →Which one of the following places does not fall on leeward slope?
- A.Pune
- B.Bengaluru
- C.Leh
- D.Mangaluru
Show answer
Mangaluru lies on the Karnataka coast, on the western, windward side of the Western Ghats. The south-west monsoon winds coming off the Arabian Sea strike the Ghats there, rise and shed heavy rain, so the coastal belt gets well over 3,000 mm a year.
Read the full explanation →Four persons are travelling to different States of India. To whom will you advise to protect oneself from blizzards ?
- A.The person travelling to Arunachal Pradesh
- B.The person travelling to Assam
- C.The person travelling to Tripura
- D.The person travelling to Odisha
Show answer
A blizzard is a severe snowstorm with strong winds, blowing snow and very low visibility, so it occurs only where there is heavy snowfall in winter.
Read the full explanation →