VFA Mixed Practice Test #273

Question 1

Dengue is spread by:

Accepted Answer

Aedes mosquito — Aedes aegypti (day-biting) transmits dengue virus; also spreads chikungunya and Zika.

Answer

Culex mosquito

Answer

Anopheles mosquito

Answer

Housefly

Question 2

Mitochondria function:

Accepted Answer

Energy (ATP) — Powerhouse of cell — produces ATP.

Answer

Protein synthesis

Answer

Digestion

Answer

Storage

Question 3

Wind turbines typically start producing electricity at wind speeds above:‌​‍

Accepted Answer

3-4 m/s (cut-in speed) — Modern wind turbines cut in at ~3-4 m/s; rated output at ~12-15 m/s; cut out at ~25 m/s.‌​‍

Answer

20 m/s

Answer

1 m/s

Answer

10 m/s

Question 4

India's rank in 2024 Olympics medal tally:‌​‍

Accepted Answer

Top 100 — India finished 71st in the Paris 2024 medal tally with 6 medals. ‌​‍Since 71 > 70, "Top 100" (≤100) is the correct bracket, not "Top 70" (≤70).

Answer

Top 30

Answer

Top 50

Answer

Top 70

Question 5

Penicillins are a class of beta-lactam antibiotics. Their antibacterial activity is primarily due to the presence of the beta-lactam ring, which acts by:

Accepted Answer

D. Inhibiting bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs). — Penicillins, like other beta-lactam antibiotics, exert their bactericidal effect by inhibiting the synthesis of the bacterial cell wall. They achieve this by covalently binding to and inactivating penicillin-binding proteins (PBPs), which are transpeptidases essential for peptidoglycan cross-linking. The other options describe mechanisms of action of different classes of antibiotics.

Answer

A. Inhibiting bacterial protein synthesis by binding to the 50S ribosomal subunit.

Answer

B. Disrupting bacterial cell membrane integrity.

Answer

C. Interfering with bacterial DNA replication.

Question 6

One metre is defined as the distance travelled by light in vacuum in:‌​‍

Accepted Answer

1/299,792,458 second — Speed of light is 299,792,458 m/s; one metre = the distance light travels in 1/299,792,458 s.‌​‍

Answer

1/1000 second

Answer

1 millisecond

Answer

1 second

Question 7

What did Werner's coordination theory (1893) propose about metal valences?‌​‍

Accepted Answer

Metal has primary (oxidation state) and secondary (coordination number) valences — Nobel 1913. ‌​‍[Co(NH₃)₆]Cl₃: primary 3 (Cl⁻), secondary 6 (NH₃). Geometry: octahedral, tetrahedral, etc.

Answer

Octet only

Answer

Primary and secondary valences

Answer

Only one valence

Question 8

Printing press by:‌​‍

Accepted Answer

Gutenberg — Johannes Gutenberg (~1440).‌​‍

Answer

Caxton

Answer

Edison

Answer

Watt

Question 9

The National Education Policy (NEP) 2020 proposes the establishment of PARAKH (Performance Assessment, Review, and Analysis of Knowledge for Holistic Development). What is the primary role envisioned for PARAKH?

Accepted Answer

C. To set norms, standards, and guidelines for student assessment and evaluation across all school boards. — PARAKH is envisioned as a National Assessment Centre with the primary role of setting norms, standards, and guidelines for student assessment and evaluation for all school boards in India. Its purpose is to shift assessment towards competency-based learning and away from rote memorization, ensuring a more holistic evaluation. It is not responsible for higher education entrance exams, financial management, or teacher recruitment.

Answer

A. To conduct a single national entrance examination for all undergraduate admissions in India.

Answer

B. To manage the financial allocation and auditing for all state education departments.

Answer

D. To recruit and train teachers for all public and private schools nationwide.

Question 10

The 10% Law in ecology states that:‌​‍

Accepted Answer

10% of energy transfers between trophic levels — Lindeman's 10% Law states that only about 10% of energy is transferred from one trophic level to the next in a food chain.‌​‍

Answer

10% of species are endangered

Answer

10% of forests are protected

Answer

10% of oceans are polluted

VFA Mixed Practice Test #273