16 public questions tagged with this topic.
**Heat engine** absorbs Q_h from hot reservoir T_h, does work W, rejects Q_c to cold T_c, efficiency η = W/Q_h =1 - Q_c/Q_h, second law limits η
Ref: NCERT > Physics Book > Thermodynamics > Second Law Heat Engines and Kelvin-Planck
**Gamma determination** γ = C_p/C_v, C_p - C_v = R, for monatomic f=3 C_v=3/2 R C_p=5/2 R γ=1.67, diatomic f=5 C_v=5/2 R C_p=7/2 R γ=1.4, adiabatic relation P V^γ = const allows γ determination from P-V measurements, slope of log P vs log V = -γ. Thermal equilibrium occurs when two systems in contact have no net heat flow between them, indicating equal temperatures, as per the Zeroth Law. Option C is correct. Using first law ΔU = Q - W, W = ∫ P dV, isobaric W = P ΔV, isothermal W = n R T ln(V₂/V₁), adiabatic P V^γ = const and η
Ref: NCERT > Physics Book > Thermodynamics > Adiabatic Processes and Gamma Determination
Angular momentum of a particle is defined as L = r×p, where r is the position vector and p is the linear momentum. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Angular momentum. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
A vaccine is best defined as immuno-biological product containing all or part of microorganism or its products, synthetic or recombinant antigens, mRNA or viral vector engineered to express antigen, formulated to induce active acquired protective immunity against specific infectious disease or tumor without causing disease itself. It comprises immunogenic principle plus diluents, stabilizers such as sucrose, surfactants, buffers maintaining pH, preservatives like 2-phenoxyethanol preventing bacterial contamination in multidose vials, and sometimes adjuvants aluminum salts, MF59, AS01 enhancing innate activation. Quality attributes include potency measured by in vitro ELISA or in vivo challenge, sterility, purity, safety, absence of extraneous agents. Unlike antibiotics that directly kill bacteria by targeting cell wall synthesis, antibiotics are therapeutic chemotherapeutics, vaccines prophylactic training host defense. Mechanism involves antigen presentation, germinal center formation, affinity maturation, memory generation measurable as neutralizing antibody titer correlate of protection. Vaccines classified prophylactic preventing infection, therapeutic treating existing disease like therapeutic cancer vaccines targeting neoantigens. Definition emphasizes immunity induction rather than direct pathogen killing, distinguishing immunobiological from chemical drug or metabolic inhibitor categories.
Ref: WHO Vaccine definition; Plotkin Vaccines 7th ed Ch 1 immunobiological; CDC NIP.
Biodiversity hotspots are regions rich in endemic species that are under constant threat from habitat loss and therefore require priority conservation.
Ref: NCERT Class 12 Biology Chapter 13: Biodiversity and Conservation Loss of Biodiversity - Causes - Habitat Loss Overexploitation
Standing crop refers to the total biomass of living organisms present in a trophic level at a given time.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Energy Flow - Food Chains Food Webs Trophic Levels
Standing crop refers to the total biomass of living organisms present in a particular trophic level at a specific time.
Ref: NCERT Class 12 Biology Chapter 12: Ecosystem Decomposition - Process and Factors
Biotechnology involves the use of living organisms, enzymes, or genetic engineering techniques to create useful products for humans.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Principles of Biotechnology - Genetic Engineering
In codominance, both alleles contribute equally to the phenotype, as seen in the AB blood group.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
A taxon is a unit of classification representing a rank or category. Species, genus, family and order are examples of taxa at different hierarchical levels.
Ref: NCERT Class 11 Biology Chapter 1: The Living World Taxonomic Categories - Species and Genus
Systematics includes identification, nomenclature and classification. It also takes evolutionary relationships among organisms into account.
Ref: NCERT Class 11 Biology Chapter 1: The Living World Nomenclature and Identification
Multiple mates in a breeding season reflects key principle in quiz on mating behavior+pyqs, where evolutionary mechanisms shape genetic variation and adaptation. In this context, Multiple mates in a breeding season aligns with experimental and theoretical evidence from population genetics, behavioral ecology and molecular phylogeny. Textbooks like Campbell Biology, Futuyma Evolution and Hartl Principles illustrate supporting data. Understanding why Multiple mates in a breeding season fits helps integrate natural selection, drift and species concepts essential for NEET, CSIR-NET and GATE examinations. This concept integrates genetics, ecology and molecular evidence, frequently tested in NEET, GATE and
Ref: Alcock, Animal Behavior, 11th ed., Chapter 11: Mating Systems.
