Q50. Who among the following scientists invented dynamite?
[SSC CHSL – 2020]
(A) Alfred Nobel
(B) Thomas Alva Edison
(C) Rudolf Diesel
(D) Benjamin Franklin
Answer: (A) Alfred Nobel
Explanation: Alfred Nobel patented dynamite in 1867 by stabilizing nitroglycerin in an absorbent material. It made blasting more manageable for construction and mining. Nobel later established prizes that reward outstanding contributions in several disciplines.
Q49. Which chemical element was discovered by William Crookes?
[SSC CGL – 2019]
(A) Germanium
(B) Beryllium
(C) Plutonium
(D) Thallium
Answer: (D) Thallium
Explanation: William Crookes discovered thallium in 1861 using spectroscopy, detecting a distinctive green spectral line. The element’s name derives from a Greek word meaning green shoot. Spectral analysis became a powerful tool for identifying previously unknown elements.
Q48. Who pioneered vaccination by developing the first successful smallpox vaccine?
[SSC CGL – 2019]
(A) John Hunter
(B) Alexander Fleming
(C) Louis Pasteur
(D) Edward Jenner
Answer: (D) Edward Jenner
Explanation: Edward Jenner demonstrated in 1796 that exposure to cowpox could protect against smallpox. This experiment began the development of vaccination as a preventive medical practice, eventually contributing to the global eradication of smallpox.
Q47. Who discovered and scientifically explained microbial fermentation?
[RPF Constable – 2019]
(A) Alexander Fleming
(B) Robert Koch
(C) Edward Jenner
(D) Louis Pasteur
Answer: (D) Louis Pasteur
Explanation: Louis Pasteur showed that fermentation is a biological process carried out by microorganisms rather than a purely chemical transformation. His investigations helped establish germ theory and led to important developments in food preservation and microbiology.
Q46. Who invented the World Wide Web in 1989?
[SSC CHSL – 2019]
(A) Charles Babbage
(B) Steve Wozniak
(C) Tim Berners-Lee
(D) Bill Gates
Answer: (C) Tim Berners-Lee
Explanation: Tim Berners-Lee proposed a hypertext-based information system at CERN in 1989. It developed into the World Wide Web, linking documents through web addresses. The Web uses the Internet but is not synonymous with the entire Internet.
Q45. Who is associated with the invention and development of alternating-current power systems?
[RRB Group D – 2018]
(A) Isaac Newton
(B) Thomas Edison
(C) Nikola Tesla
(D) Albert Einstein
Answer: (C) Nikola Tesla
Explanation: Nikola Tesla made major contributions to practical polyphase alternating-current generation and motors. Alternating current itself emerged through work by multiple inventors; Tesla’s systems were especially important for economical long-distance electrical transmission.
Q44. Who developed a theory of nuclear forces based on exchange particles?
[RRB Group D – 2018]
(A) Satyendra Nath Bose
(B) Hideki Yukawa
(C) Jagadish Chandra Bose
(D) J. J. Thomson
Answer: (B) Hideki Yukawa
Explanation: Hideki Yukawa proposed that the strong nuclear force between nucleons could be explained through exchange of a massive particle later called a meson. His theoretical work earned the 1949 Nobel Prize in Physics.
Q43. Which ancient Greek thinker used the term atomos for an indivisible particle?
[RRB Group D – 2018]
(A) John Dalton
(B) Kanada
(C) Antoine Lavoisier
(D) Democritus
Answer: (D) Democritus
Explanation: Democritus proposed that matter is composed of tiny indivisible units called atomos. His idea was philosophical rather than experimental. Scientific atomic theory emerged much later through measurements and work by chemists such as John Dalton.
Q42. Who is most closely associated with the periodic table of chemical elements?
[RRB Group D – 2018]
(A) John Newlands
(B) Friedrich Hund
(C) Dmitri Mendeleev
(D) Alfred Nobel
Answer: (C) Dmitri Mendeleev
Explanation: Dmitri Mendeleev published an influential periodic table in 1869 based largely on recurring properties and atomic masses. He left gaps for undiscovered elements and predicted their characteristics, an important reason his classification was widely adopted.
Q41. Who invented the smart glove known as TJay, designed to help predict epileptic seizures?
[RRB Group D – 2018]
(A) Rajlakshmi Borthakur
(B) Ankita Deka
(C) Archana S. R.
(D) Chayanika Baruah
Answer: (A) Rajlakshmi Borthakur
Explanation: Rajlakshmi Borthakur developed the TJay smart glove concept to monitor physiological signals linked with seizures. Such wearable inventions show how sensors and computing can be integrated to provide early alerts, though performance depends on careful clinical validation.
