In the 1870s, two inventors Elisha Gray and Alexander Graham Bell both independently designed devices that could transmit speech electrically (the telephone). Both men rushed their respective designs to the patent office within hours of each other; Alexander Graham Bell patented his telephone first. Elisha Gray and Alexander Graham Bell entered into a famous legal battle over the invention of the telephone, which Bell won.

Correct Option: B

In the 1870s, two inventors Elisha Gray and Alexander Graham Bell both independently designed devices that could transmit speech electrically (the telephone). Both men rushed their respective designs to the patent office within hours of each other; Alexander Graham Bell patented his telephone first. Elisha Gray and Alexander Graham Bell entered into a famous legal battle over the invention of the telephone, which Bell won.

Sir James Young Simpson was a Scottish and an important figure in the history of medicine. Simpson discovered the anaesthetic properties of chloroform and successfully introduced it for general medical use. Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous. Several million tons are produced annually as a precursor to Teflon and refrigerants, but its use for refrigerants is being phased out.

Correct Option: A

Sir James Young Simpson was a Scottish and an important figure in the history of medicine. Simpson discovered the anaesthetic properties of chloroform and successfully introduced it for general medical use. Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous. Several million tons are produced annually as a precursor to Teflon and refrigerants, but its use for refrigerants is being phased out.

The smallpox vaccine was the first successful vaccine to be developed. The process of vaccination was first publicised by Edward Jenner in 1796, who acted upon his observation that milkmaids who caught the cowpox virus did not catch smallpox. Before the introduction of a vaccine, the mortality of the severe form of smallpox—variola major—was very high. Historical records show that a method of inducing immunity was already known. A process called inoculation, also known as insufflation or variolation was practiced in India as early as 1000 BC.

Correct Option: B

The smallpox vaccine was the first successful vaccine to be developed. The process of vaccination was first publicised by Edward Jenner in 1796, who acted upon his observation that milkmaids who caught the cowpox virus did not catch smallpox. Before the introduction of a vaccine, the mortality of the severe form of smallpox—variola major—was very high. Historical records show that a method of inducing immunity was already known. A process called inoculation, also known as insufflation or variolation was practiced in India as early as 1000 BC.

X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Röntgen, who is usually credited as its discoverer, and who had named it Xradiation to signify an unknown type of radiation.

Correct Option: B

X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Röntgen, who is usually credited as its discoverer, and who had named it Xradiation to signify an unknown type of radiation.

Martin Cooper (born December 26, 1928 in Chicago, Illinois, USA) is an American former Motorola vice president and division manager who in the 1970s led the team that developed the handheld mobile phone (as distinct from the car phone). Cooper was also the CEO and founder of ArrayComm, a company that works on smart antenna technology and wireless networks, and was the corporate director of Research and Development for Motorola. In 1973, when Motorola installed a base station to handle the first public demonstration of a phone call over the cellular network, the company was trying to persuade the Federal Communications Commission to allocate frequency space to private companies for use in the emerging technology of cellular communications. After some initial testing in Washington for the F.C.C., John F. Mitchell and his team, which included Martin Cooper, took the cellular phone technology to New York to demonstrate it to reporters and the public.

Correct Option: D

Martin Cooper (born December 26, 1928 in Chicago, Illinois, USA) is an American former Motorola vice president and division manager who in the 1970s led the team that developed the handheld mobile phone (as distinct from the car phone). Cooper was also the CEO and founder of ArrayComm, a company that works on smart antenna technology and wireless networks, and was the corporate director of Research and Development for Motorola. In 1973, when Motorola installed a base station to handle the first public demonstration of a phone call over the cellular network, the company was trying to persuade the Federal Communications Commission to allocate frequency space to private companies for use in the emerging technology of cellular communications. After some initial testing in Washington for the F.C.C., John F. Mitchell and his team, which included Martin Cooper, took the cellular phone technology to New York to demonstrate it to reporters and the public.