Which one of the following pairs is NOT correctly matched?

The correct answer is C, X-Rays. Roentgen, a German physicist, noticed in 1895 that a screen in his darkened laboratory glowed while a covered discharge tube was running, and he named the unknown radiation X-rays. For this he received the first Nobel Prize in Physics in 1901. Option A is wrong because the conservation of electric charge is a principle established through the work of Benjamin Franklin and others, not a discovery of Roentgen. Option B is wrong because a practical incandescent electric bulb was made by Thomas Alva Edison in 1879, sixteen years before the X-ray. Option D is wrong because thermodynamics grew out of the work of Carnot, Joule, Clausius and Kelvin and is a body of laws rather than a single discovery. Remember the pairing of Roentgen, X-rays, 1895 and the first physics Nobel of 1901 together.

The correct answer is C, Edward Jenner. In 1796 Jenner showed that material from a cowpox sore protected a boy against smallpox, the first deliberate vaccination, and the word vaccine itself comes from vacca, the Latin for cow. That experiment founded the science of immunology. Option A is wrong because Robert Koch identified the bacteria that cause tuberculosis and cholera and gave the rules for linking a microbe to a disease, so he belongs to bacteriology. Option B is wrong because Louis Pasteur gave the germ theory of disease, pasteurisation and the rabies vaccine, and is called the father of microbiology, although his vaccine work came after Jenner. Option D is wrong because Karl Landsteiner discovered the human blood groups. The trap in this question is Pasteur, whose fame in vaccines makes candidates skip the earlier name.

The correct answer is B, Alexander Graham Bell. Bell received the patent for the telephone in 1876 and made the first call over a wire, carrying the human voice itself rather than a code. Option A is wrong because Samuel Morse built the electric telegraph in 1837 and gave the dot and dash code that bears his name, which sent messages but not speech. Option C is wrong because Guglielmo Marconi developed practical wireless telegraphy in the 1890s and sent signals across the Atlantic in 1901, again as code and without wires. Option D is wrong because Thomas Alva Edison, though he improved the telephone transmitter, is remembered for the practical electric bulb and the phonograph. The examiner keeps Morse and Marconi in the options precisely because all three men worked on sending messages over a distance.

The correct answer is A, Alfred Nobel. The Swedish chemist Alfred Nobel patented dynamite in 1867, a safe way of handling nitroglycerine, and the fortune he made from explosives endowed the Nobel Prizes, first awarded in 1901. Option B is wrong because Rudolf Diesel invented the compression ignition engine that carries his name, not an explosive. Option C is wrong because Michael Faraday discovered electromagnetic induction and built the first dynamo, a machine that generates electricity; the similarity between the words dynamite and dynamo is exactly the trap the paper setter is laying. Option D is wrong because James Watt improved the steam engine, and the unit of power is named after him. Keep the chain in mind: Nobel, dynamite, 1867, and the prizes that began in 1901 on the anniversary of his death, 10 December.

The correct answer is B, Alexander Fleming. Fleming noticed in 1928 that a mould of the genus Penicillium had killed the bacteria growing around it on a culture plate, and the substance he named penicillin became the first antibiotic; Florey and Chain later turned it into a usable drug and shared the Nobel Prize with him. Option A is wrong because Joseph Lister introduced antiseptic surgery using carbolic acid, which prevents infection during an operation rather than curing one. Option C is wrong because Jonas Salk developed the injectable polio vaccine in the 1950s, a vaccine and not an antibiotic. Option D is wrong because Robert Koch identified disease causing bacteria but did not find a drug against them. A vaccine prevents a disease and an antibiotic kills bacteria already in the body, and papers test that distinction.