Study HubHubPage 70/114Scan verified MCQs with the answer highlighted, then open explanations when you want the reasoning.
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Winds And Local Atmospheric Phenomena
What is the name of the cold and dense air blowing down from the mountain slope during the night?
Katabatic wind refers to the cold, dense air that flows downhill from mountain slopes during the night due to cooling of the air at higher elevations. This matches the description in the question.
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Common Nicknames Of Natural Resources
Black gold is oil; Black diamond is ____?
The term 'black gold' commonly refers to oil due to its high value and color, while 'black diamond' is a colloquial term for coal, which is black and valuable as a fuel source.
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Physical Properties Of Minerals
"Mohs’ Scale" is used to indicate the ______?
Mohs' Scale is a well-known scale used to measure the hardness of minerals, ranking them from 1 (talc) to 10 (diamond). It does not measure viscosity, elasticity, or brittleness.
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Membrane Transport
The movement of any solvent across a semipermeable membrane is called __________?
Osmosis is the process by which a solvent, typically water, moves across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. This matches the definition given in the question.
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Vector And Scalar Quantities
Which one of the following is not a vector quantity?
Speed is a scalar quantity because it only has magnitude and no direction, whereas acceleration, displacement, and force are vector quantities as they have both magnitude and direction.
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Mirrors
A dental mirror is what type of mirror?
A dental mirror is typically a convex mirror because it provides a wider field of view, allowing dentists to see more area inside the mouth. Concave mirrors focus light and are not used for this purpose, while plane mirrors do not offer the expanded view needed.
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Atmospheric Layers
Which layer of the atmosphere reflects radio waves back to the Earth’s surface?
The ionosphere is a layer of the Earth's atmosphere that is ionized by solar radiation and is capable of reflecting radio waves back to the Earth's surface, enabling long-distance radio communication.
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Electricity
Which instrument measures electric force?
A voltmeter is the instrument used to measure electric potential difference, which relates to electric force in circuits. An ammeter measures current, not electric force. Hygrometer measures humidity, and hydrometer measures liquid density.
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Planets
Which planet is the most dense and heaviest?
Earth is the most dense and heaviest planet in the Solar System. While Jupiter is the largest by size and mass, its average density is much lower than Earth's due to its gaseous composition.
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Foundations Of Science
Which of the following sciences is considered the "mother of all sciences"?
Mathematics is often called the 'mother of all sciences' because it provides the foundational language and tools used in all scientific disciplines to analyze and understand phenomena.