Current Affairs MCQs – Page 44 (Q431-440)

James Clerk Maxwell, a Scottish physicist, formulated the classical theory of electromagnetism in the 1860s, unifying electricity, magnetism and light into a single elegant set of mathematical equations known as Maxwell's equations. His work predicted the existence of electromagnetic waves traveling at the speed of light, later confirmed experimentally by Heinrich Hertz. Heinrich Hertz, Andre-Marie Ampere and Michael Faraday are tempting distractors, as each made important earlier or later contributions to the study of electricity and magnetism that Maxwell helped mathematically unify. Einstein later cited Maxwell's work as a major inspiration for his own theory of relativity.

J.J. Thomson, an English physicist, discovered the electron in 1897 through experiments with cathode ray tubes, identifying it as a subatomic particle far smaller and lighter than the atom itself, which had previously been thought indivisible. His discovery fundamentally overturned the classical view of the atom as the smallest unit of matter. Ernest Rutherford, James Chadwick and Niels Bohr are tempting distractors, as each made later, related discoveries about atomic structure, including the nucleus, the neutron and electron energy levels respectively. Thomson won the 1906 Nobel Prize in Physics for his discovery of the electron.

Ernest Rutherford, a New Zealand-born physicist, is credited with discovering the atomic nucleus in 1911 through his famous gold foil experiment, which revealed that atoms consist mostly of empty space with a tiny, dense, positively charged core. This discovery fundamentally reshaped the model of atomic structure used in physics and chemistry ever since. Niels Bohr, J.J. Thomson and James Chadwick are tempting distractors, with Bohr later building directly on Rutherford's nuclear model to describe electron energy levels. Rutherford is often called the father of nuclear physics and had earlier won the 1908 Nobel Prize in Chemistry for his work on radioactivity.

James Chadwick, an English physicist, discovered the neutron in 1932, identifying the electrically neutral subatomic particle that, together with protons, makes up the nucleus of an atom. His discovery resolved a long-standing puzzle about atomic mass and paved the way for the later development of nuclear fission and nuclear weapons. Niels Bohr, Ernest Rutherford and J.J. Thomson are tempting distractors, as each made earlier, related discoveries about atomic structure that set the stage for Chadwick's work. Chadwick won the 1935 Nobel Prize in Physics for discovering the neutron and later played a key role in Britain's wartime atomic bomb research.

Hubert Cecil Booth, a British engineer, is credited with inventing the first motorized vacuum cleaner in 1901, a large, horse-drawn machine that used suction to remove dirt, a significant advance over earlier manual carpet-cleaning devices. His invention was inspired by watching a demonstration of a dust-blowing cleaning machine and wondering whether suction would work better instead. James Murray Spangler, William Hoover and James Dyson are tempting distractors, with Spangler and Hoover later developing the smaller, more practical upright vacuum cleaner design familiar in homes today. Dyson, in the late 20th century, revolutionized the vacuum cleaner further with bagless cyclonic suction technology.

Elias Howe, an American inventor, is credited with inventing the modern lockstitch sewing machine in 1846, a design that used a needle with an eye near its point and a shuttle to create a durable, mechanized stitch. His invention dramatically sped up garment production, though it took years of legal battles to defend his patent against competitors. Barthelemy Thimonnier, Isaac Singer and Walter Hunt are tempting distractors, with Thimonnier having built an earlier French sewing machine and Singer later commercializing and popularizing the sewing machine for widespread home use. The sewing machine transformed the textile and garment industries during the Industrial Revolution.

Walter Hunt, an American inventor, is credited with inventing the safety pin in 1849, reportedly designing it in just a few hours to pay off a small debt, then selling the patent rights for a modest sum. His simple but ingenious design added a clasp and a coiled spring to a basic pin, protecting users from being accidentally pricked. Elias Howe, Whitcomb Judson and John Loud are tempting distractors, as each is instead credited with other inventions, the sewing machine, an early zipper design and the ballpoint pen respectively. Hunt was a prolific but often financially unlucky inventor who also designed an early repeating rifle.

Laszlo Biro, a Hungarian-Argentine journalist and inventor, is credited with inventing the modern ballpoint pen in the late 1930s, developing a reliable ink-delivery mechanism using a rotating ball at the tip that solved the smudging problems of earlier fountain pens. He patented his design after fleeing to Argentina to escape the persecution of Jews in Europe before World War II. Lewis Waterman, John Loud and George Parker are tempting distractors, as each is instead associated with earlier pen technologies, including the fountain pen and an unsuccessful early ballpoint patent. Ballpoint pens are still commonly called biro pens in several English-speaking countries in his honor.

Whitcomb Judson, an American inventor, is credited with inventing an early version of the zip fastener in 1893, originally called a clasp locker, designed to fasten shoes more conveniently than traditional buttons. His design was later significantly improved and made more reliable by Swedish-American engineer Gideon Sundback in 1913, whose refined version became the modern zipper. Elias Howe, Walter Hunt and Gideon Sundback are tempting distractors, with Howe having actually patented an even earlier, less successful fastening device decades before Judson. The zipper eventually became widely used in clothing, luggage and countless other everyday products.

Louis Daguerre, a French artist and photographer, is regarded as a pioneer of practical photography, developing the daguerreotype process in the 1830s, the first publicly announced and commercially viable photographic method. His process produced a highly detailed image on a silver-coated copper plate, though each image was unique and could not be reproduced like later negative-based photography. Joseph Niepce, George Eastman and Thomas Edison are tempting distractors, with Niepce having actually collaborated with Daguerre and produced an even earlier, cruder photographic image, and Eastman later popularizing accessible roll-film photography with Kodak. The French government purchased Daguerre's process and released it freely to the world in 1839.