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True or False: Heisenberg's uncertainty principle states that position and momentum cannot be precisely measured simultaneously.
- True
- False
Answer: True
Δx·Δp ≥ h/4π: fundamental limit in quantum mechanics, not due to measurement errors. Highlights probabilistic nature of microscopic world. [[NCERT Physics Class 12]]
True or False: Algorithmic bias in AI systems can perpetuate social inequalities.
- True
- False
Answer: True
AI trained on biased data may discriminate in hiring, lending, policing. Ethical AI requires fairness, transparency, accountability. Emerging topic for governance sections. [[NITI Aayog Principles for Responsible AI]]
True or False: The half-life of a first-order reaction is independent of initial concentration.
- True
- False
Answer: True
t₁/₂ = 0.693/k for first-order reactions. Unlike zero/second-order, it doesn't depend on [A]₀. Useful for radioactive decay calculations. [[NCERT Chemistry Class 12]]
Which complex exhibits geometrical isomerism?
- [Ni(CN)₄]²⁻
- [Co(NH₃)₆]³⁺
- [Pt(NH₃)₂Cl₂]
- [Fe(CN)₆]⁴⁻
Answer: [Pt(NH₃)₂Cl₂]
Square planar [Pt(NH₃)₂Cl₂] shows cis-trans isomerism. Tetrahedral/octahedral symmetric complexes don't. Important for stereochemistry in coordination compounds. [[NCERT Chemistry Class 12]]
Tollens' reagent is used to distinguish aldehydes from ketones by producing a ________ mirror.
- Gold
- Silver
- Copper
- Platinum
Answer: Silver
Tollens' test: Aldehydes reduce [Ag(NH₃)₂]⁺ to metallic silver (silver mirror); ketones don't react. Classic test for carbonyl compounds. [[NCERT Chemistry Class 12]]
The Tyndall effect is observed in ________.
- True solutions
- Colloids
- Suspensions
- Pure liquids
Answer: Colloids
Tyndall effect: scattering of light by colloidal particles, making beam visible. True solutions don't scatter; suspensions settle. Used to distinguish colloids. [[NCERT Chemistry Class 12]]
True or False: Incomplete dominance results in a blended phenotype in heterozygotes.
- True
- False
Answer: True
Incomplete dominance: heterozygote shows intermediate phenotype (e.g., red × white snapdragon → pink). Differs from codominance (both alleles expressed, e.g., AB blood group). [[NCERT Biology Class 12]]
For a spontaneous process at constant T and P, the Gibbs free energy change (ΔG) must be ________.
- Positive
- Negative
- Zero
- Infinite
Answer: Negative
ΔG = ΔH - TΔS. If ΔG < 0, process is spontaneous; ΔG > 0, non-spontaneous; ΔG = 0, equilibrium. Unifies enthalpy and entropy for predicting reaction feasibility. [[NCERT Chemistry Class 11]]
The work function of a metal is the minimum energy required to:
- Excite an electron
- Remove an electron from the surface
- Ionize an atom
- Break a chemical bond
Answer: Remove an electron from the surface
Work function (φ) is the threshold energy for photoelectric emission. Einstein's equation: K_max = hν - φ. Central to quantum explanation of photoelectric effect. [[NCERT Physics Class 12]]
Which molecule exhibits hydrogen bonding?
- CH₄
- HCl
- NH₃
- H₂S
Answer: NH₃
Hydrogen bonding occurs when H is bonded to highly electronegative N, O, or F. NH₃ forms intermolecular H-bonds, explaining its high boiling point vs. PH₃. Critical for molecular properties. [[NCERT Chemistry Class 11]]
True or False: In blockchain, each block contains a cryptographic hash of the previous block.
- True
- False
Answer: True
This chaining via hashes ensures immutability: altering one block changes its hash, breaking the chain. Combined with consensus mechanisms, it provides security and transparency. [[NITI Aayog Reports]]
The de Broglie wavelength of a particle is inversely proportional to its ________.
- Energy
- Momentum
- Mass
- Velocity
Answer: Momentum
de Broglie hypothesis: λ = h/p, where p = momentum. Establishes wave-particle duality for matter. Verified by electron diffraction experiments. Foundational quantum mechanics. [[NCERT Physics Class 12]]
For a zero-order reaction, the unit of rate constant is ________.
- s⁻¹
- mol L⁻¹ s⁻¹
- L mol⁻¹ s⁻¹
- mol² L⁻² s⁻¹
Answer: mol L⁻¹ s⁻¹
Zero-order: rate = k, so k has same units as rate (concentration/time). First-order: s⁻¹; Second-order: L mol⁻¹ s⁻¹. Unit analysis helps identify reaction order. [[NCERT Chemistry Class 12]]
Young's double-slit experiment demonstrates the ________ nature of light.
- Particle
- Wave
- Dual
- Electromagnetic
Answer: Wave
Interference fringes in Young's experiment confirm light's wave nature (superposition principle). Photoelectric effect shows particle nature. Together they establish wave-particle duality. [[NCERT Physics Class 12]]
The coordination number of cobalt in [Co(NH₃)₆]Cl₃ is ________.
- 3
- 4
- 5
- 6
Answer: 6
Coordination number = number of ligand donor atoms bonded to central metal. Here, six NH₃ molecules coordinate to Co³⁺, giving octahedral geometry. Key concept in Werner's theory. [[NCERT Chemistry Class 12]]
True or False: In an adiabatic process, heat exchange with surroundings is zero.
- True
- False
Answer: True
Adiabatic process: Q=0, so ΔU = -W. Temperature changes due to work done. Applies to rapid compression/expansion (e.g., diesel engine, atmospheric phenomena). [[NCERT Physics Class 11]]
In volumetric analysis, the point at which the reaction is just complete is called the ________ point.
- End
- Equivalence
- Neutralization
- Titration
Answer: Equivalence
Equivalence point: stoichiometric completion of reaction. End point: indicator color change (ideally matches equivalence). Distinction is critical for accurate titrations. [[NCERT Chemistry Class 11]]
Which transition metal is used as a catalyst in the Haber process for ammonia synthesis?
- Nickel
- Iron
- Platinum
- Copper
Answer: Iron
Finely divided iron with Mo promoter catalyzes N₂ + 3H₂ → 2NH₃ at high pressure/temperature. Haber process is crucial for fertilizer production. Important industrial application of transition metals. [[NCERT Chemistry Class 12]]
The Montreal Protocol (1987) primarily addresses the phase-out of:
- Greenhouse gases
- Ozone-depleting substances
- Plastic waste
- Nuclear waste
Answer: Ozone-depleting substances
Montreal Protocol targets CFCs, halons, and other ODS to protect stratospheric ozone. It's considered one of the most successful environmental treaties. India ratified it in 1992. [[UNEP, NCERT Geography Class 11]]
Which compound gives violet color with neutral FeCl₃ solution?
- Ethanol
- Phenol
- Diethyl ether
- Methanol
Answer: Phenol
Phenol forms colored complexes with FeCl₃ (violet for phenol), used as a test for phenolic -OH group. Alcohols do not give this test. Important for organic qualitative analysis. [[NCERT Chemistry Class 12]]