Most Explosive Type of Volcano is
Answer: B
Rhyolite caldera complexes are the most explosive volcanoes of all.
Their magma is silica-rich, so it is extremely viscous and traps gas until the pressure blows the whole chamber apart and its roof collapses into a caldera. Yellowstone and Toba are examples; a single eruption can eject thousands of cubic kilometres.
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Where are the Macronutrients located on a Nutritional Label?
Answer: A
The macronutrients - fat, carbohydrate and protein - are listed at the top of a nutrition label, immediately under the serving size and calories.
Vitamins and minerals, the micronutrients, follow lower down. The order reflects the quantities in which the body needs them.
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The weight of an object will be minimum when it is placed at ?
Answer: D
An object weighs least at the centre of the earth, where it weighs nothing at all.
There the mass of the earth surrounds it equally in every direction, so the pulls cancel exactly and \( g = 0 \). Weight is greatest at the poles, where the radius is smallest and there is no rotational effect.
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Thumba Equatorial Rocket Launching Station (TERLS) is situated in?
Answer: B
The Thumba Equatorial Rocket Launching Station is at Thumba near Thiruvananthapuram, in Kerala.
It was chosen because it lies almost on the magnetic equator, which suits the study of the equatorial electrojet. India's first sounding rocket was launched from it in November 1963.
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The isotope of uranium capable of sustaining chain reaction is
Answer: A
Uranium-235 is the isotope that sustains a chain reaction. It fissions when it absorbs a slow neutron and releases two or three more, which can go on to split further nuclei.
It makes up only 0.7 per cent of natural uranium; the rest is U-238, which does not fission with slow neutrons. Enrichment raises the U-235 fraction for reactor fuel.
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Which of the following is not an intensive property?
Answer: A
Weight is not an intensive property. It depends on how much material there is, which makes it extensive.
Density, refractive index and melting point are intensive: they are the same for a drop of water as for a lake of it.
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When an acid reacts with a metal carbonate, the products formed are _____________
Answer: D
An acid reacting with a metal carbonate gives a salt, water and carbon dioxide:
\[ \mathrm{Na_2CO_3 + 2HCl \rightarrow 2NaCl + H_2O + CO_2} \]
The effervescence of carbon dioxide is the standard laboratory test for a carbonate; the gas turns limewater milky.
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The accumulation of stress along the boundaries of lithospheric plates results in which of the following?
Answer: A
Stress accumulating along the boundaries of lithospheric plates is released as earthquakes. The rocks lock, strain builds, and eventually the fault slips and the stored elastic energy radiates as seismic waves.
This is why the world's earthquake belts trace the plate boundaries almost exactly.
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Nautical mile is a unit of distance used in
Answer: A
The nautical mile is used in navigation at sea and in the air. It equals 1,852 m, defined as one minute of arc of latitude along a meridian.
That definition is what makes it useful: a degree of latitude is 60 nautical miles, so distance can be read straight off a chart's latitude scale.
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The solar eclipse occurs when
Answer: C
A solar eclipse occurs when the moon comes between the sun and the earth, casting its shadow on the earth's surface.
This can happen only at new moon. When the earth comes between the sun and the moon, the moon passes into the earth's shadow and there is a lunar eclipse instead.
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