Answers to CE MC Questions (1992-2000)

PLATE TECTONICS

Earth Structure & Plate Margins

Year	Ans.	Explanation
9501	A	(4) is wrong. Crust consists of silica, aluminium and magnesium. Mantle consists of iron and magnesium. Core consists of iron and nickel.
9913	C	A deep oceanic trench can only be found in destructive plate boundary where subduction occurs.
9911	B	The oceanic plate should be of higher density than the continental plate.
9716	D	Eurasian plate and North American plates are moving apart (diverging) and leads to the formation of mid-oceanic ridge.
9201	A	The greater the depth of the earth, the higher the density.
9202	D
9402	B	X is the Mid-Atlantic Ridge (an oceanic ridge). An ocean trench cannot be found there. Please note the difference between an oceanic ridge and an oceanic trench.
9733	D	Submergence of the ocean refers to the reduction of sea level. Vulcanicity is shown by the formation of granite, which is an intrusive igneous rock. River erosion can be found along rivers on the mountains. Sedimentation is evident by the occurrence of sandstone.
9803	A	The continental plate never subducts under the oceanic plate as it is of lower density.
9204	B	Volcanoes are formed by vulcanicity while fold mountains are formed by folding.
0013	A	X is a destructive plate margin between one oceanic plate and one continental plate. Mid-oceanic ridge is found in constructive plate boundary. Volcanic island arc is found in destructive plate margin between 2 oceanic plates.
9503	B

Answers to CE MC Questions (1992-2000)

PLATE TECTONICS

Folding & Faulting

Year	Ans.	Explanation
9801	B	The diagram shows a recumbent fold. It is formed by folding which is caused by compressional forces.
0012	C	Y is not a line of fracture as it is not formed by faulting.
9912	C	A normal fault is caused by tension.
9502	B	The rock strata show that it is a type of sedimentary rock. No evidence supports that Z is a kind of igneous rock, nor there is any igneous intrusion around the region.
9342	C	The slope X is formed by faulting, which is a kind of tectonic activity.
9711	A	The coin is horizontally placed on the rock. It is obvious a tear fault with two blocks of rock moving horizontally.
9401	B	The Himalayas should be located in the zone of convergence which is a destructive plate margin.
9302	D
9607	B	Reverse fault is formed by compression, which is not found in the diagram.
9719	B	Volcanic plug and caldera are formed by vulcanicity.
9721	B
9606	C

Answers to CE MC Questions (1992-2000)

PLATE TECTONICS

Vulcanicity

Year	Ans.	Explanation
0011	C
0015	D	X shows veins which are scars left behind after vulcanicity.
9403	A	Dyke and batholith are found under the earth crust as they are formed by intrusive vulcanicity.
9804	C
9805	A	Magma is found below the earth crust. (4) is irrelevant to the question.
9249	D	The lake is a crater lake.
9250	A
9203	C	The cooling rate of intrusive igneous activities is lower than extrusive igneous activities as they have contact with the air.
9802	C	Vulcanicity is rarely found in conservative plate margins.
9724	B