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The process of heating ore below melting point in absence of air is called ________.
- Roasting
- Calcination
- Smelting
- Refining
Answer: Calcination
Calcination decomposes carbonate ores (e.g., ZnCO₃ → ZnO + CO₂) by heating in limited air. Roasting is for sulfide ores in excess air. Key step in metal extraction. [[NCERT Chemistry Class 12]]
True or False: PM2.5 refers to particulate matter with diameter less than 2.5 micrometers.
- True
- False
Answer: True
PM2.5 particles are fine inhalable particles (≤2.5 μm) that penetrate deep into lungs, causing respiratory/cardiovascular issues. Monitored under National Air Quality Index. [[CPCB Reports, NCERT Geography Class 11]]
Photoelectric effect demonstrates the ________ nature of light.
- Wave
- Particle
- Dual
- Electromagnetic
Answer: Particle
Einstein explained photoelectric effect using photons (light quanta), showing particle behavior. This contributed to quantum theory. Wave nature is shown by interference/diffraction. [[NCERT Physics Class 12]]
The gap between two neurons is called ________.
- Synapse
- Axon
- Dendrite
- Myelin sheath
Answer: Synapse
Synapse is the junction where neurotransmitters transmit signals from one neuron to another. Essential for understanding nerve impulse transmission and brain function. [[NCERT Biology Class 11]]
True or False: In a galvanic cell, oxidation occurs at the cathode.
- True
- False
Answer: False
In galvanic (voltaic) cells: oxidation at anode (loss of e⁻), reduction at cathode (gain of e⁻). Mnemonic: 'AnOx RedCat'. Critical for electrochemistry problems. [[NCERT Chemistry Class 12]]
ISRO's Mars Orbiter Mission is also known as:
- Chandrayaan-1
- Mangalyaan
- Gaganyaan
- Aditya-L1
Answer: Mangalyaan
Mangalyaan (Mars Orbiter Mission) made India the first Asian nation to reach Mars orbit (2014). It studied Martian surface and atmosphere. Important for current affairs and science sections. [[ISRO Reports, NCERT Geography Class 11]]
Heat transfer through direct contact is called ________.
- Convection
- Radiation
- Conduction
- Advection
Answer: Conduction
Conduction occurs via molecular collisions in solids (e.g., metal rod heating). Convection involves fluid movement; radiation uses electromagnetic waves. Basic thermodynamics concept. [[NCERT Physics Class 11]]
True or False: Darwin's theory of natural selection states that organisms with advantageous traits are more likely to survive and reproduce.
- True
- False
Answer: True
Natural selection is the mechanism of evolution where heritable traits enhancing survival/reproduction become more common over generations. Foundational concept in biology. [[NCERT Biology Class 12]]
Which of the following is a natural polymer?
- Polythene
- PVC
- Cellulose
- Nylon
Answer: Cellulose
Cellulose (in plant cell walls) is a natural polymer of glucose. Polythene, PVC, Nylon are synthetic polymers. Understanding polymer types is important for materials science. [[NCERT Chemistry Class 12]]
Rainwater harvesting helps in recharging ________ water.
- Surface
- Ground
- Distilled
- Saline
Answer: Ground
Harvested rainwater percolates into aquifers, replenishing groundwater tables. Critical for sustainable water management in water-stressed regions like India. [[CGWB Reports, NCERT Geography Class 11]]
True or False: Nuclear fusion powers the Sun and stars.
- True
- False
Answer: True
In stellar cores, hydrogen nuclei fuse into helium under extreme temperature/pressure, releasing vast energy (E=mc²). Fusion differs from fission (splitting heavy nuclei). Key astrophysics concept. [[NCERT Physics Class 12]]
CRISPR-Cas9 is a technology used for:
- DNA sequencing
- Gene editing
- Protein synthesis
- Cloning
Answer: Gene editing
CRISPR-Cas9 allows precise modification of DNA sequences by cutting at targeted locations. It has applications in medicine, agriculture, and research. Emerging topic for science and tech sections. [[DBT Reports, NCERT Biology Class 12]]
The ozone layer in stratosphere absorbs harmful ________ radiation from the sun.
- Infrared
- Visible
- Ultraviolet
- Radio
Answer: Ultraviolet
Ozone (O₃) absorbs 97-99% of Sun's medium-frequency UV-B and UV-C rays, protecting life from DNA damage. Ozone depletion by CFCs is a major environmental concern. [[NCERT Chemistry Class 11, UNEP Reports]]
True or False: Phishing is a type of malware that encrypts files for ransom.
- True
- False
Answer: False
Phishing is social engineering (fraudulent emails) to steal credentials. Ransomware encrypts files for payment. Distinguishing cyber threats is important for digital literacy sections. [[CERT-In Guidelines, NCERT Computer Science]]
Which device converts mechanical energy into electrical energy?
- Motor
- Generator
- Transformer
- Inverter
Answer: Generator
Generators work on electromagnetic induction (Faraday's Law): rotating coil in magnetic field induces current. Motors do the reverse. Crucial for power generation concepts. [[NCERT Physics Class 10]]
The functional unit of kidney is called ________.
- Neuron
- Nephron
- Alveolus
- Villus
Answer: Nephron
Nephrons filter blood, reabsorb nutrients, and produce urine. Each kidney has ~1 million nephrons. Understanding nephron structure is vital for physiology questions. [[NCERT Biology Class 11]]
True or False: Catalysts increase the activation energy of a chemical reaction.
- True
- False
Answer: False
Catalysts lower activation energy, speeding up reactions without being consumed. They provide alternative pathways. Enzymes are biological catalysts. Key concept in chemical kinetics. [[NCERT Chemistry Class 12]]
Which color bin is used for biodegradable waste in India's segregation system?
- Green
- Blue
- Red
- Yellow
Answer: Green
As per Solid Waste Management Rules 2016: Green bin = wet/biodegradable waste (food scraps); Blue = dry/recyclable; Red = domestic hazardous. Important for civic awareness questions. [[MoHUA Guidelines, NCERT Geography Class 11]]
The distance between two consecutive crests of a wave is called ________.
- Amplitude
- Frequency
- Wavelength
- Time period
Answer: Wavelength
Wavelength (λ) is the spatial period of a wave. Related to frequency (f) and speed (v) by v = fλ. Fundamental for understanding sound, light, and electromagnetic waves. [[NCERT Physics Class 11]]
True or False: Antibiotics are effective against viral infections like common cold.
- True
- False
Answer: False
Antibiotics target bacterial cell structures/processes. Viruses lack these targets and require antivirals or vaccines. Misuse of antibiotics causes resistance—a major public health issue. [[NCERT Biology Class 12, WHO Guidelines]]