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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]]
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]]
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]]
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]]
True or False: Like magnetic poles attract each other.
- True
- False
Answer: False
Like poles (N-N or S-S) repel; unlike poles (N-S) attract. This fundamental law of magnetism applies to bar magnets, electromagnets, and Earth's magnetic field. [[NCERT Physics Class 10]]
The number of protons in an atom determines its ________ number.
- Mass
- Atomic
- Neutron
- Electron
Answer: Atomic
Atomic number (Z) = proton count, defining an element's identity and position in periodic table. Mass number = protons + neutrons. Foundational concept in chemistry. [[NCERT Chemistry Class 11]]
True or False: India is one of the 17 megadiverse countries in the world.
- True
- False
Answer: True
India hosts ~7-8% of global species despite having 2.4% of land area. It has four biodiversity hotspots: Himalayas, Indo-Burma, Sundaland, Western Ghats. Important for environment and geography sections. [[MoEFCC Reports, NCERT Biology Class 12]]
The commercial unit of electrical energy is:
- Joule
- Watt
- Kilowatt-hour
- Volt-ampere
Answer: Kilowatt-hour
1 kWh = energy consumed by a 1 kW device running for 1 hour = 3.6×10⁶ Joules. Electricity bills use kWh. Understanding units is crucial for numerical problems. [[NCERT Physics Class 10]]
The value of acceleration due to gravity (g) on Earth's surface is approximately ________ m/s².
- 8.9
- 9.8
- 10.2
- 11.0
Answer: 9.8
Standard gravity (g) is 9.8 m/s², varying slightly with altitude and latitude. It's derived from Newton's law of gravitation (g = GM/R²). Essential for mechanics problems in physics. [[NCERT Physics Class 11]]
True or False: Decomposers like fungi and bacteria convert organic matter into inorganic nutrients.
- True
- False
Answer: True
Decomposers break down dead organisms, recycling nutrients (nitrogen, phosphorus) into soil for producers. This sustains ecosystem productivity and is vital for biogeochemical cycles. [[NCERT Biology Class 12]]
The Paris Agreement aims to limit global warming to well below ________°C above pre-industrial levels.
- 1.5
- 2.0
- 2.5
- 3.0
Answer: 2.0
The 2015 Paris Agreement targets limiting global temperature rise to well below 2°C, preferably 1.5°C, to mitigate climate change impacts. India is a signatory committed to Nationally Determined Contributions (NDCs). [[UNFCCC, NCERT Geography Class 11]]
Which blood vessel carries oxygenated blood from the heart to the body?
- Pulmonary artery
- Pulmonary vein
- Aorta
- Vena cava
Answer: Aorta
The aorta is the main artery carrying oxygen-rich blood from the left ventricle to systemic circulation. Pulmonary artery carries deoxygenated blood to lungs. Critical for understanding human physiology. [[NCERT Biology Class 11]]
True or False: Wi-Fi uses radio waves for wireless communication.
- True
- False
Answer: True
Wi-Fi operates on 2.4 GHz or 5 GHz radio frequency bands to transmit data wirelessly between devices and routers. Understanding this helps in troubleshooting network issues and cybersecurity awareness. [[NCERT Computer Science]]
The process by which plants lose water vapor through stomata is called ________.
- Photosynthesis
- Respiration
- Transpiration
- Guttation
Answer: Transpiration
Transpiration is the evaporation of water from plant leaves via stomata. It aids in water uptake, nutrient transport, and cooling. Excessive transpiration can cause wilting. Key concept in botany. [[NCERT Biology Class 11]]
True or False: Rusting of iron is a physical change.
- True
- False
Answer: False
Rusting (formation of hydrated iron(III) oxide) is a chemical change involving oxidation of iron in presence of oxygen and water. It alters chemical composition, unlike physical changes like melting. Important for basic chemistry concepts. [[NCERT Chemistry Class 10]]
One light year is a unit of ________.
- Time
- Distance
- Speed
- Intensity
Answer: Distance
A light year is the distance light travels in one year in vacuum (~9.46 trillion km). It's used in astronomy to measure vast interstellar distances, not time. Common trick question in exams. [[NCERT Physics Class 11]]