Science – GK Questions

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]]

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]]

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]]

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 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]]

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]]

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]]

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]]

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]]

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]]

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]]

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]]

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]]