Welcome, Guest
General Science MCQ Practice
Practice General Science questions with instant scoring, correct answer highlighting, detailed solutions and first-click AI explanation caching for missing explanations.
📚 Questions: 553
🧭 Page: 49 / 56
🎯 10 per page
Correct: 0/10
Wrong: 0/10
Correct
Wrong
Accuracy
Q. 763
👁 1 views
Which one is the hardest form of carbon ?
Correct option: C — Diamond.
- Reason: Diamond has a three‑dimensional covalent network with each carbon atom sp3‑hybridized in a tetrahedral lattice, giving extremely strong bonds and high hardness.
- Key concept: Hardness arises from strong covalent bonds in a rigid crystal lattice.
- Formula/numerical logic: No formula required; hardness relates to bond strength and crystal structure.
- Exam tip: Remember Mohs scale ranking: Diamond > Quartz > Graphite in terms of hardness; graphite is soft due to layered structure.
- Why others are incorrect: Coke, charcoal are carbonized forms with weaker structures; graphite has layers that slip easily, making it soft.
Q. 762
👁 1 views
The gas used for artificial ripening of green fruit is:
Explanation:
- Correct answer: A. Ethylene – Ethylene is a plant hormone (gas) that triggers ripening in many climacteric fruits (e.g., bananas, tomatoes).
- Key concept: Gas-phase ethylene induces enzymes that soften fruit, convert starch to sugar, and change color.
- Formula (mention): C2H4 (typical ethylene molecule).
- Why others are incorrect: Ethane is just a hydrocarbon, not a ripening hormone; CO2 is used to modify atmosphere and slow or control ripening, not induce it.
Q. 761
👁 1 views
Ozone hole refers to :
Correct option: C
- Why correct: The "ozone hole" means decreased thickness of the ozone layer in the stratosphere, not a literal hole.
- Key concept: Ozone concentration isMeasured in Dobson Units; depletion reduces thickness, especially over polar regions.
- Why others are incorrect:
- AMisleading—no actual hole forms.
- B Describes overall decrease, not the localized thinning/hole concept.
- D Opposite effect; thickness increases.
- Exam tip: Remember: "ozone hole" = thinning, not a physical gap.
Q. 760
👁 1 views
Mesons are found in
Answer: D
- Reason: Mesons are strongly interacting particles (hadrons) made of a quark and an antiquark. They appear in high-energy cosmic ray interactions in the atmosphere (air showers), producing pions and kaons.
- Key concept: Strong interaction; hadrons vs. electromagnetic radiation. Mesons are not components of laser beams, X-rays, or gamma rays.
- Simple note: In cosmic rays, primary particles collide with atmospheric nuclei, creating mesons that decay quickly.
- Exam tip: If a question asks where mesons are found, think of high-energy hadronic processes, not EM waves.
Q. 759
👁 1 views
Nuclear fission is caused by the impact of
Correct answer: A
- Concept: Nuclear fission is typically induced when a neutron is absorbed by a heavy nucleus, causing it to become unstable and split.
- Why not others: Protons, deuterons, or electrons do not efficiently trigger fission in heavy nuclei under normal conditions.
- Key idea: Neutron-induced fission enables chain reactions since neutrons released can cause more fissions.
- Tip: Remember “neutron-induced fission” as the common mechanism in reactors and weapon physics.
Q. 754
👁 1 views
'Beans' is associated with computer programming language :
Correct answer: Java
- Reason: The term "Beans" is strongly associated with JavaBeans, a component architecture in Java for reusable software components.
- Key concept: JavaBeans are serializable, have a no-arg constructor, and use getters/setters for properties, enabling easy GUI and enterprise app components.
- Why others are incorrect: C++, COBOL, and PASCAL do not have a standard concept named "Beans" in their ecosystems.
- Exam tip: If a wording mentions components/beans in programming, think Java.
Q. 732
👁 1 views
Who was the first Indian to go into space ?
A former Indian Air Force pilot. In the year 1984.
Q. 704
👁 1 views
Ozone layer is situated in the upper regions of
Correct answer: B. Stratosphere
- The ozone layer is located in the stratosphere, roughly 10–50 km above Earth's surface, peaking around 20–30 km.
- Key concept: O3 absorbs harmful UV radiation. Formation: O2 + hv → 2O; O + O2 → O3.
- Exam tip: Remember “Ozone = Stratosphere, not Troposphere.”
- Why others are incorrect: Troposphere is where weather occurs; Mesosphere is higher and thinner; Magnetosphere is not a atmospheric layer.
Q. 687
👁 1 views
The longest day in the southern Hemisphere is on :
Answer: A (22nd December)
- The longest day in the Southern Hemisphere occurs at the summer solstice when Earth's axial tilt (about 23.5°) tilts closest to the Sun.
- In the Southern Hemisphere, this happens around December 21–22, giving the maximum daylight.
- Other dates are the winter solstice (June 21) or equinoxes (March 21, September 23), which do not give the longest day.
- Exam tip: Remember opposite seasons for hemispheres—when one has summer solstice, the other has winter solstice.
Q. 647
👁 1 views
Acid rain is caused due to the pollution of environment by:
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air
Correct: 0/10
Wrong: 0/10
Correct
Wrong
Accuracy
0%