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Question 881

'ASTROSAT' is a satellite launched by ISRO for :

AResearch on climate conditon

BBetter Tele-communication

CAstronomy research

DNone of these

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C. Astronomy researchExplanation: ASTROSAT is India’s first dedicated multi-wavelength space observatory launched by ISRO (Indian Space Research Organisation) on September 28, 2015. It is designed for astronomy research and studies celestial objects like stars, galaxies, black holes, and neutron stars in different wavelengths — including visible, ultraviolet, and X-ray bands. ASTROSAT helps scientists study high-energy astrophysical phenomena and provides data comparable to international missions such as NASA’s Hubble Space Telescope.

Question 803

The element common to all acids is :

AOxygen

BHydrogen

CNitrogen

DSulphur

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B. HydrogenExplanation: The element hydrogen is common to all acids. Acids are substances that produce hydrogen ions (H⁺) or hydronium ions (H₃O⁺) when dissolved in water. This property gives acids their characteristic sour taste, the ability to turn blue litmus paper red, and to react with bases to form salts and water. Examples include hydrochloric acid (HCl), sulphuric acid (H₂SO₄), and nitric acid (HNO₃)—all of which release hydrogen ions in aqueous solution.

Question 802

Which of the following processes is responsible for transforming liquid into vapour ?

ACondensation

BEvaporation

CTranspiration

DSublimation

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B. EvaporationExplanation not yet available.

Question 801

The intensity of earthquake is measured by :

ABarometer

BHydrometer

CPolygraph

DSeismograph

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D. SeismographExplanation: The intensity and magnitude of an earthquake are measured using a scientific instrument called a seismograph. It records the vibrations or seismic waves produced by earthquakes. The data obtained from a seismograph are used to calculate the earthquake’s strength on scales such as the Richter Scale or the Moment Magnitude Scale. The seismogram (the recorded graph) shows the amplitude and duration of the waves, helping scientists locate the earthquake’s epicenter and determine its severity.

Question 800

Chemical name of 'Baking powder' is :

AAmmonium Chloride

BMagnesium Phosphate

CSodium bi-carbonate

DAmmonium bi-phosphate

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C. Sodium bi-carbonateExplanation: The chemical name of baking powder is sodium bicarbonate (NaHCO₃), also known as baking soda. It is a mild alkali used in cooking and baking as a leavening agent. When heated or mixed with an acid (like vinegar, lemon juice, or cream of tartar), it decomposes to release carbon dioxide gas (CO₂). The bubbles of CO₂ make the dough rise and become soft and spongy. In commercial baking powder, sodium bicarbonate is often mixed with a weak acid and a drying agent.

Question 799

Which of the following gases constitutes the major portion of the atmosphere by volume ?

AOxygen

BArgon

CNitrogen

DCarbon dioxide

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C. NitrogenExplanation: Nitrogen (N₂) constitutes the major portion of the Earth's atmosphere by volume — about 78%. It is a colorless, odorless, and inert gas that plays a vital role in maintaining atmospheric stability and supporting life through the nitrogen cycle. Oxygen makes up about 21% of the atmosphere and is essential for respiration and combustion. Other gases like argon (~0.93%) and carbon dioxide (~0.04%) are present in much smaller amounts.

Question 762

How much time the light from Sun takes to reach the Earth ?

A2 minutes

B4 minutes

C8 minutes

D12 minutes

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C. 8 minutesExplanation: Light from the Sun takes approximately 8 minutes and 20 seconds to reach the Earth. The average distance between the Earth and the Sun is about 149.6 million kilometers (1 Astronomical Unit). Since light travels at a speed of 3 × 108 meters per second in a vacuum, it covers this distance in roughly eight minutes. This means that when we see sunlight, we are actually seeing it as it was about eight minutes earlier.

Question 761

Which one is the hardest form of carbon ?

ACoke

BGraphite

CDiamond

DCharcoal

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C. DiamondExplanation: Diamond is the hardest natural form of carbon. In diamond, each carbon atom is covalently bonded to four other carbon atoms in a tetrahedral structure, forming a strong three-dimensional lattice. This arrangement makes diamond extremely hard, dense, and transparent. It is used in cutting, drilling, and polishing tools. In contrast, graphite (another allotrope of carbon) is soft and slippery because its carbon atoms are arranged in layers with weak forces between them.

Question 760

The gas used for artificial ripening of green fruit is:

AEthylene

BEthane

CCarbon dioxide

DNone of these

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A. EthyleneExplanation: The gas used for artificial ripening of green fruits is ethylene (C₂H₄). Ethylene is a natural plant hormone that regulates fruit ripening by stimulating the conversion of starches into sugars, making the fruit softer and sweeter. In artificial ripening, ethylene gas is introduced in controlled amounts to uniformly ripen fruits such as bananas, mangoes, and tomatoes. However, the use of harmful chemicals like calcium carbide for ripening is banned because it produces toxic substances like acetylene.

Question 759

Ozone hole refers to :

Ahole in Ozone layer

Bdecrease in the Ozone layer

Cdecrease in thickness of Ozone layer

Dincrease in thickness of Ozone layer

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C. decrease in thickness of Ozone layerExplanation: The term "Ozone hole" does not mean an actual hole but refers to a significant decrease in the thickness of the ozone layer in the Earth's stratosphere. This thinning occurs mainly over the Antarctic region during spring (September–November) due to chemical reactions involving chlorofluorocarbons (CFCs) and other ozone-depleting substances. These chemicals release chlorine and bromine atoms, which destroy ozone (O₃) molecules. The thinning allows more harmful ultraviolet (UV) radiation to reach the Earth's surface, causing health and environmental hazards.

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Science

'ASTROSAT' is a satellite launched by ISRO for :

The element common to all acids is :

Which of the following processes is responsible for transforming liquid into vapour ?

The intensity of earthquake is measured by :

Chemical name of 'Baking powder' is :

Which of the following gases constitutes the major portion of the atmosphere by volume ?

How much time the light from Sun takes to reach the Earth ?

Which one is the hardest form of carbon ?

The gas used for artificial ripening of green fruit is:

Ozone hole refers to :

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