Create a custom practice set
Pick category, difficulty, number of questions, and time limit. Start instantly with your own quiz.
Generate QuizGK Questions
Filter by category, type, and difficulty. Reading is open for everyone.
True or False: Alkenes undergo addition reactions due to the presence of pi bonds.
- True
- False
Answer: True
Pi bonds in C=C are weaker and more reactive than sigma bonds, allowing addition of H₂, X₂, HX, etc. Alkanes (only sigma bonds) undergo substitution. Core organic reaction mechanism. [[NCERT Chemistry Class 11]]
BOD stands for:
- Biological Oxygen Demand
- Biochemical Oxygen Demand
- Bacterial Oxygen Demand
- Basic Oxygen Demand
Answer: Biochemical Oxygen Demand
BOD measures oxygen required by microbes to decompose organic matter in water. High BOD indicates severe pollution. Critical parameter in water quality assessment. [[CPCB Guidelines, NCERT Biology Class 12]]
The hormone that promotes fruit ripening in plants is ________.
- Auxin
- Gibberellin
- Cytokinin
- Ethylene
Answer: Ethylene
Ethylene is a gaseous plant hormone triggering ripening, senescence, and abscission. Commercially used for artificial ripening of bananas, mangoes. Important for agriculture questions. [[NCERT Biology Class 11]]
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]]
Which molecule has a linear geometry?
- H₂O
- NH₃
- CO₂
- CH₄
Answer: CO₂
CO₂ has sp hybridization with two double bonds, resulting in linear shape (180° bond angle). H₂O (bent), NH₃ (pyramidal), CH₄ (tetrahedral). VSEPR theory application. [[NCERT Chemistry Class 11]]
ISRO's launch vehicle that uses cryogenic engines in its upper stage is ________.
- PSLV
- GSLV
- SSLV
- ASLV
Answer: GSLV
GSLV (Geosynchronous Satellite Launch Vehicle) uses indigenous cryogenic upper stage (CE-7.5/CE-20) for launching heavy satellites to GTO. PSLV uses solid/liquid stages. Key for space tech awareness. [[ISRO Reports]]
True or False: A test cross is performed between a dominant phenotype individual and a homozygous recessive individual.
- True
- False
Answer: True
Test cross determines genotype of dominant phenotype: if any recessive offspring appear, the parent is heterozygous. Fundamental tool in Mendelian genetics. [[NCERT Biology Class 12]]
Control rods in nuclear reactors are made of materials that:
- Amplify neutrons
- Absorb neutrons
- Reflect neutrons
- Moderate neutrons
Answer: Absorb neutrons
Control rods (cadmium/boron) absorb excess neutrons to regulate fission chain reaction. Moderators (heavy water/graphite) slow neutrons. Essential for understanding nuclear energy. [[NCERT Physics Class 12]]
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]]
True or False: Kaziranga National Park in Assam is a UNESCO World Heritage Site primarily for the Indian one-horned rhinoceros.
- True
- False
Answer: True
Kaziranga (inscribed 1985) hosts ~70% of world's greater one-horned rhinos. It also protects tigers, elephants, and wetland biodiversity. Important for environment and geography exams. [[UNESCO, MoEFCC Reports]]
Which of the following is a virus that causes AIDS?
- HBV
- HIV
- HSV
- HPV
Answer: HIV
HIV (Human Immunodeficiency Virus) attacks CD4+ T-cells, weakening the immune system. Untreated HIV infection leads to AIDS. Awareness of pathogens is crucial for health sections. [[NCERT Biology Class 12, NACO Guidelines]]
The spectral series of hydrogen lying in the visible region is called ________ series.
- Lyman
- Balmer
- Paschen
- Brackett
Answer: Balmer
Balmer series (n=2 to higher levels) produces visible lines (Hα, Hβ, etc.). Lyman is UV, Paschen/Brackett are IR. Understanding spectral series is key for atomic structure questions. [[NCERT Physics Class 12]]
True or False: Two-factor authentication (2FA) enhances security by requiring two different types of credentials.
- True
- False
Answer: True
2FA combines something you know (password) with something you have (OTP/app) or something you are (biometric). This layered approach significantly reduces unauthorized access risks. [[CERT-In Guidelines, NCERT Computer Science]]
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]]
Jaundice is characterized by yellowing of skin and eyes due to accumulation of ________.
- Urea
- Bilirubin
- Creatinine
- Uric acid
Answer: Bilirubin
Bilirubin, a yellow pigment from hemoglobin breakdown, accumulates in blood due to liver dysfunction, bile duct obstruction, or excessive RBC destruction. Key diagnostic indicator in medicine. [[NCERT Biology Class 11]]
True or False: Modulation is the process of superimposing a low-frequency signal onto a high-frequency carrier wave.
- True
- False
Answer: True
Modulation (AM/FM) enables efficient transmission of audio/video signals over long distances by shifting them to higher frequencies suitable for antenna radiation. Core concept in telecommunications. [[NCERT Physics 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]]
The Contact Process is used for the industrial production of ________ acid.
- Nitric
- Hydrochloric
- Sulfuric
- Phosphoric
Answer: Sulfuric
Contact Process oxidizes SO₂ to SO₃ using V₂O₅ catalyst, then absorbs in H₂SO₄ to form oleum. Sulfuric acid is vital for fertilizers, batteries, and chemicals. Important industrial chemistry. [[NCERT Chemistry Class 12]]
True or False: Bryophytes are known as amphibians of the plant kingdom because they require water for fertilization.
- True
- False
Answer: True
Bryophytes (mosses, liverworts) need water for sperm to swim to egg during fertilization, though they live on land. This dual dependency earns them the 'amphibians' title. Key concept in plant evolution. [[NCERT Biology Class 11]]
Which element is commonly used as a dopant to create n-type semiconductors?
- Boron
- Aluminum
- Phosphorus
- Gallium
Answer: Phosphorus
Phosphorus (Group 15) has 5 valence electrons. When doped into silicon (Group 14), the extra electron becomes free for conduction, creating n-type semiconductor. Boron creates p-type. Fundamental for electronics. [[NCERT Physics Class 12]]