Van Leeuwenhoek discovered “protozoa” - the single-celled organisms and he called them “animalcules”. He also improved the microscope and laid foundation for microbiology. He is often cited as the first microbiologist to study muscle fibers, bacteria, spermatozoa and blood flow in capillaries. Although, he did not have much education or a scientific background, yet he defied all odds to be reckoned as a great scientist through his skillful observations, insight and unmatched curiosity. He revolutionized biological science by exposing microscopic life to the world.

Correct Option: A

Van Leeuwenhoek discovered “protozoa” - the single-celled organisms and he called them “animalcules”. He also improved the microscope and laid foundation for microbiology. He is often cited as the first microbiologist to study muscle fibers, bacteria, spermatozoa and blood flow in capillaries. Although, he did not have much education or a scientific background, yet he defied all odds to be reckoned as a great scientist through his skillful observations, insight and unmatched curiosity. He revolutionized biological science by exposing microscopic life to the world.

The North Pole is the northernmost point on the Earth, lying diametrically opposite the South Pole. It defines geodetic latitude 90° North as well as the direction of true north. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value. Robert Edwin Peary was an American explorer who claimed to have led the first expedition, on April 6, 1909, to reach the geographic North Pole.

Correct Option: B

The North Pole is the northernmost point on the Earth, lying diametrically opposite the South Pole. It defines geodetic latitude 90° North as well as the direction of true north. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value. Robert Edwin Peary was an American explorer who claimed to have led the first expedition, on April 6, 1909, to reach the geographic North Pole.

Cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word “cement” traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. Joseph Aspdin was a British cement manufacturer who obtained the patent for Portland cement on 21 October 1824.

Correct Option: C

Cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word “cement” traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. Joseph Aspdin was a British cement manufacturer who obtained the patent for Portland cement on 21 October 1824.

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.

An optical fiber (or optical fibre) is a flexible, transparent fiber made of glass (silica) or plastic, slightly thicker than a human hair. It functions as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Narinder Singh Kapany (born 31 October 1926 in Moga, Punjab, India) is an Indian born American physicist invented optical fibre.

Correct Option: B

An optical fiber (or optical fibre) is a flexible, transparent fiber made of glass (silica) or plastic, slightly thicker than a human hair. It functions as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Narinder Singh Kapany (born 31 October 1926 in Moga, Punjab, India) is an Indian born American physicist invented optical fibre.