Q30. Who invented the Space Pen?
[SSC CGL – 2017]
(A) Paul C. Fisher
(B) Rudolf Diesel
(C) Wright brothers
(D) Alexander Fleming
Answer: (A) Paul C. Fisher
Explanation: Paul C. Fisher developed a pressurized ink cartridge that could write in unusual orientations and low-gravity conditions. Fisher Space Pens were adopted for space missions. The pen does not depend on gravity alone to feed ink toward its tip.
Q29. Who invented the electrocardiogram (ECG) instrument?
[SSC CGL – 2017]
(A) Willem Einthoven
(B) Edward Jenner
(C) Antonio de Ulloa and Charles Wood
(D) Karl Benz
Answer: (A) Willem Einthoven
Explanation: Willem Einthoven developed the string galvanometer and advanced electrocardiography around the beginning of the twentieth century. An ECG records electrical activity associated with the heartbeat and is widely used to assess heart rhythm and other cardiac conditions.
Q28. Who invented an early practical television system?
[SSC CGL – 2017]
(A) Michael Faraday
(B) Joseph Henry
(C) Abbé Caselli
(D) John Logie Baird
Answer: (D) John Logie Baird
Explanation: John Logie Baird demonstrated an early mechanical television system in the 1920s. His apparatus transmitted moving visual images, preceding the widespread adoption of fully electronic television, which developed through contributions by several other inventors.
Q27. Who invented the hook-and-loop fastener known as Velcro?
[SSC CGL – 2017]
(A) Thomas Edison
(B) William Harvey
(C) George de Mestral
(D) Robert Boyle
Answer: (C) George de Mestral
Explanation: Swiss engineer George de Mestral conceived hook-and-loop fastening after observing how burdock burrs attached to clothing and animal fur. The resulting Velcro system uses tiny hooks and loops to make a reusable fastener.
Q26. Who discovered the proton?
[SSC CGL – 2017]
(A) Ernest Rutherford
(B) Friedrich Miescher
(C) Henri Becquerel
(D) Henry Cavendish
Answer: (A) Ernest Rutherford
Explanation: Rutherford identified the hydrogen nucleus as a fundamental positively charged particle through nuclear-reaction experiments reported around 1917–1919. This particle came to be called the proton and forms part of every ordinary atomic nucleus.
Q25. Who discovered the planet Uranus?
[SSC CGL – 2017]
(A) Isaac Newton
(B) William Henry Fox Talbot
(C) William Herschel
(D) Nicolaus Copernicus
Answer: (C) William Herschel
Explanation: William Herschel observed Uranus in 1781 and initially thought it might be a comet. Follow-up observations revealed its planetary orbit, making it the first planet discovered in modern times with the help of a telescope.
Q24. Who is credited with describing the circulation of blood through the human body?
[SSC CGL – 2017]
(A) Thomas Edison
(B) William Harvey
(C) Robert Hooke
(D) Robert Boyle
Answer: (B) William Harvey
Explanation: William Harvey published a systematic explanation of blood circulation in 1628. He argued that the heart pumps blood around the body continuously, overturning longstanding theories and establishing an important basis for cardiovascular physiology.
Q23. Who introduced the idea of light quanta, later called photons?
[SSC CGL – 2017]
(A) George Crum
(B) Albert Einstein
(C) Henry Cavendish
(D) Humphry Davy
Answer: (B) Albert Einstein
Explanation: Albert Einstein proposed in 1905 that light exchanges energy in discrete packets, explaining features of the photoelectric effect. These light quanta became known as photons. The idea contributed decisively to the development of quantum physics.
Q22. Who is associated with the discovery of insulin?
[SSC CGL – 2017]
(A) Alexander Fleming
(B) Frederick Banting
(C) James Watt
(D) F. G. Hopkins
Answer: (B) Frederick Banting
Explanation: Frederick Banting and Charles Best played central roles in isolating insulin in 1921, working with J. J. R. Macleod and James Collip. Insulin transformed diabetes management by making it possible to treat deficient insulin production.
Q21. Who invented a commercially important form of stainless steel?
[RRB NTPC – 2016]
(A) William Howard Livens
(B) Joseph Aspdin
(C) Harry Brearley
(D) James Dyson
Answer: (C) Harry Brearley
Explanation: Harry Brearley developed an early stainless steel alloy in 1913 while researching corrosion-resistant steel. Chromium forms a protective oxide layer, helping the metal resist rust. Stainless steel later became essential in manufacturing, medicine and household products.
