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The general formula for alkanes is ________.
- CₙH₂ₙ
- CₙH₂ₙ₊₂
- CₙH₂ₙ₋₂
- CₙHₙ
Answer: CₙH₂ₙ₊₂
Alkanes are saturated hydrocarbons with single bonds: CₙH₂ₙ₊₂ (e.g., methane CH₄, ethane C₂H₆). Alkenes: CₙH₂ₙ; Alkynes: CₙH₂ₙ₋₂. Foundational organic chemistry. [[NCERT Chemistry Class 11]]
Yeast used in baking and brewing belongs to the kingdom ________.
- Monera
- Protista
- Fungi
- Plantae
Answer: Fungi
Yeast (Saccharomyces cerevisiae) is a unicellular fungus. It ferments sugars to produce CO₂ (leavens bread) and ethanol (in brewing). Important for applied biology. [[NCERT Biology Class 11]]
Which electromagnetic wave has the longest wavelength?
- Gamma rays
- X-rays
- Visible light
- Radio waves
Answer: Radio waves
EM spectrum order (longest to shortest wavelength): Radio > Microwave > IR > Visible > UV > X-ray > Gamma. Radio waves used in communication; gamma rays in cancer treatment. [[NCERT Physics Class 12]]
Aadhaar is a ________-digit unique identity number issued by UIDAI.
- 10
- 12
- 14
- 16
Answer: 12
Aadhaar is a 12-digit biometric ID for Indian residents, enabling access to subsidies and services. Part of Digital India initiative for inclusive governance. [[UIDAI Reports, NCERT Computer Science]]
Adsorption of gases on solid surfaces is an ________ process.
- Endothermic
- Exothermic
- Isothermal
- Adiabatic
Answer: Exothermic
Adsorption releases heat (ΔH < 0) as gas molecules lose freedom on surface. Desorption is endothermic. Important for catalysis and purification processes. [[NCERT Chemistry Class 12]]
The longest bone in the human body is the ________.
- Humerus
- Femur
- Tibia
- Fibula
Answer: Femur
Femur (thigh bone) is the longest and strongest bone, supporting body weight and enabling movement. Critical for anatomy questions in exams. [[NCERT Biology Class 11]]
Ohm's law states that V = I × ________.
- Power
- Resistance
- Capacitance
- Inductance
Answer: Resistance
Ohm's Law: Voltage (V) = Current (I) × Resistance (R). Valid for ohmic conductors at constant temperature. Foundation for circuit analysis. [[NCERT Physics Class 10]]
Planting trees in rows to reduce wind speed and prevent soil erosion is called ________.
- Contour ploughing
- Terracing
- Shelter belts
- Crop rotation
Answer: Shelter belts
Shelter belts (windbreaks) are rows of trees/shrubs that reduce wind erosion, conserve moisture, and protect crops. Part of sustainable agriculture practices. [[NCERT Geography Class 11, MoA Reports]]
The element responsible for the hardness of diamond is ________.
- Silicon
- Carbon
- Boron
- Nitrogen
Answer: Carbon
Diamond is an allotrope of carbon with tetrahedral sp³ hybridization, forming a rigid 3D network. This structure gives extreme hardness. Graphite is another carbon allotrope with different properties. [[NCERT Chemistry Class 11]]
The hormone insulin is secreted by the ________ of pancreas.
- Alpha cells
- Beta cells
- Delta cells
- Acinar cells
Answer: Beta cells
Pancreatic beta cells (in Islets of Langerhans) secrete insulin, which lowers blood glucose by facilitating cellular uptake. Deficiency causes diabetes mellitus. Key physiology concept. [[NCERT Biology Class 11]]
The SI unit of luminous intensity is ________.
- Lumen
- Lux
- Candela
- Watt
Answer: Candela
Candela (cd) is one of seven SI base units, measuring luminous intensity in a given direction. Lumen measures total luminous flux; lux measures illuminance. Important for photometry. [[NCERT Physics Class 11]]
Biogas primarily consists of ________ and carbon dioxide.
- Hydrogen
- Methane
- Oxygen
- Nitrogen
Answer: Methane
Biogas (from anaerobic digestion of organic waste) contains 50-75% methane (CH₄), a clean fuel. Promoted under GOBAR-DHAN scheme for rural energy and waste management. [[MNRE Reports, NCERT Chemistry Class 11]]
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]]
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]]
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]]
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]]
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]]
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]]
1 Byte equals ________ bits.
- 4
- 8
- 16
- 32
Answer: 8
1 Byte = 8 bits (binary digits). This standard unit conversion is essential for understanding computer memory, data transfer rates, and digital storage concepts. [[NCERT Computer Science]]