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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]]
Solar energy is converted into electrical energy using:
- Wind turbines
- Photovoltaic cells
- Hydroelectric dams
- Biogas plants
Answer: Photovoltaic cells
Photovoltaic (PV) cells in solar panels convert sunlight directly into electricity via the photovoltaic effect. This clean energy technology is promoted under India's National Solar Mission. [[MNRE Reports, NCERT Geography Class 11]]
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]]
True or False: Prokaryotic cells have a well-defined nucleus.
- True
- False
Answer: False
Prokaryotes (e.g., bacteria) lack a membrane-bound nucleus; their DNA floats in the nucleoid region. Eukaryotes (plants, animals) have a true nucleus. This distinction is fundamental in biology classification. [[NCERT Biology Class 11]]
Which metal is liquid at room temperature?
- Sodium
- Mercury
- Iron
- Aluminum
Answer: Mercury
Mercury (Hg) is the only metal liquid at standard room temperature (25°C) due to weak metallic bonding. It's used in thermometers, barometers, and electrical switches. Bromine is the only non-metal liquid at room temperature. [[NCERT Chemistry Class 10]]
HTTP stands for ________ Transfer Protocol.
- Hyper Text
- High Text
- Hyper Transfer
- High Transfer
Answer: Hyper Text
HTTP (HyperText Transfer Protocol) is the foundation of data communication on the World Wide Web. It enables loading of web pages using hypertext links. HTTPS adds encryption for security. Crucial for computer awareness sections. [[NCERT Computer Science]]
True or False: According to the second law of thermodynamics, entropy of an isolated system always decreases.
- True
- False
Answer: False
The second law states that entropy (disorder) of an isolated system never decreases; it either increases or remains constant. This explains irreversibility of natural processes and is fundamental in physics and engineering. [[NCERT Physics Class 11]]
Which disease is caused by the deficiency of Vitamin C?
- Rickets
- Scurvy
- Beri-Beri
- Night Blindness
Answer: Scurvy
Scurvy results from Vitamin C deficiency, causing weakened collagen synthesis, leading to bleeding gums, joint pain, and poor wound healing. Citrus fruits are rich sources of Vitamin C. Important for health-related exam questions. [[NCERT Biology Class 11]]
The chemical formula of common salt is ________.
- KCl
- NaCl
- CaCl₂
- MgCl₂
Answer: NaCl
Sodium chloride (NaCl) is common table salt, formed by ionic bonding between sodium (Na⁺) and chloride (Cl⁻) ions. It's essential for nerve function and fluid balance in humans. [[NCERT Chemistry Class 10]]
True or False: Eutrophication is caused by excessive nitrogen and phosphorus in water bodies.
- True
- False
Answer: True
Eutrophication occurs when nutrient runoff (from fertilizers, sewage) causes algal blooms. Depleted oxygen levels from decomposing algae kill aquatic life. It's a major water pollution issue addressed in environmental policies. [[NCERT Biology Class 12, CPCB Reports]]
Sound waves cannot travel through:
- Solid
- Liquid
- Gas
- Vacuum
Answer: Vacuum
Sound requires a medium (solid, liquid, or gas) to propagate as mechanical waves. In vacuum, there are no particles to vibrate, so sound cannot travel. This explains why space is silent. [[NCERT Physics Class 9]]
The enzyme pepsin is secreted by the ________ in the stomach.
- Liver
- Pancreas
- Gastric glands
- Salivary glands
Answer: Gastric glands
Gastric glands in the stomach lining secrete pepsinogen, which converts to active pepsin in acidic environment. Pepsin breaks down proteins into peptides, initiating protein digestion. This is a key concept in human physiology. [[NCERT Biology Class 11]]
True or False: RAM is a type of non-volatile memory.
- True
- False
Answer: False
RAM (Random Access Memory) is volatile memory, meaning it loses stored data when power is turned off. Non-volatile memories like ROM, SSDs, or hard drives retain data without power. This distinction is critical in computer architecture. [[NCERT Computer Science]]
Which of the following is a strong acid?
- Acetic Acid
- Citric Acid
- Hydrochloric Acid
- Carbonic Acid
Answer: Hydrochloric Acid
HCl completely dissociates in water into H⁺ and Cl⁻ ions, making it a strong acid. Weak acids like acetic acid only partially dissociate. Strong acids are highly corrosive and used in industrial processes. [[NCERT Chemistry Class 10]]
The SI unit of electric current is ________.
- Volt
- Ohm
- Ampere
- Watt
Answer: Ampere
Ampere (A) is the SI base unit for electric current, defined as one coulomb of charge passing a point per second. Named after physicist André-Marie Ampère, it's fundamental in electrical engineering and daily applications. [[NCERT Physics Class 10]]
True or False: Mitochondrial DNA is inherited only from the father.
- True
- False
Answer: False
Mitochondrial DNA (mtDNA) is maternally inherited in humans. Sperm mitochondria are typically degraded after fertilization, so offspring inherit mtDNA exclusively from the mother. This is crucial for evolutionary studies and forensic analysis. [[NCERT Biology Class 12]]
Which gas is primarily responsible for the greenhouse effect?
- Oxygen
- Nitrogen
- Carbon Dioxide
- Argon
Answer: Carbon Dioxide
CO₂ traps infrared radiation emitted by Earth's surface, preventing heat escape into space. While water vapor contributes most naturally, human activities have significantly increased CO₂ levels, accelerating global warming. [[IPCC Reports, NCERT Geography Class 11]]
The element with atomic number 1 is ________.
- Helium
- Hydrogen
- Lithium
- Oxygen
Answer: Hydrogen
Hydrogen (H) has atomic number 1, meaning it has one proton in its nucleus. It is the lightest and most abundant element in the universe, forming the basis of organic chemistry. [[NCERT Chemistry Class 11]]
True or False: The speed of light is maximum in glass compared to vacuum.
- True
- False
Answer: False
Light travels fastest in vacuum (≈3×10⁸ m/s). In denser media like glass, light slows down due to refraction, with speed reducing to about 2×10⁸ m/s. This principle is fundamental in optics. [[NCERT Physics Class 12]]
Which part of the human brain is responsible for maintaining balance and posture?
- Cerebrum
- Cerebellum
- Medulla Oblongata
- Hypothalamus
Answer: Cerebellum
The cerebellum, located at the back of the brain, coordinates voluntary movements, maintains posture, and ensures balance. It receives sensory input and fine-tunes motor activities. [[NCERT Biology Class 11]]