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.

Mycobacteriumleprae, the causative agent of leprosy, was discovered by G. H. Armauer Hansen in Norway in 1873. Hansen observed a number of nonrefractile small rods in unstained tissue sections. The rods were not soluble in potassium lye, and they were acid- and alcohol-fast. In 1879, he was able to stain these organisms with Ziehl’s method and the similarities with Koch’s bacillus (Mycobacterium tuberculosis) were noted.

Correct Option: A

Mycobacteriumleprae, the causative agent of leprosy, was discovered by G. H. Armauer Hansen in Norway in 1873. Hansen observed a number of nonrefractile small rods in unstained tissue sections. The rods were not soluble in potassium lye, and they were acid- and alcohol-fast. In 1879, he was able to stain these organisms with Ziehl’s method and the similarities with Koch’s bacillus (Mycobacterium tuberculosis) were noted.

Otto Hahn, (8 March 1879 – 28 July 1968) was a German chemist and Nobel laureate, a pioneer in the fields of radioactivity and radiochemistry. He is regarded as “the father of nuclear chemistry”. Hahn was a courageous opposer of Jewish persecution by the Nazi Party and after World War II he became a passionate campaigner against the use of nuclear energy as a weapon. He served as the last President of the Kaiser Wilhelm Society (KWG) in 1946 and as the founding President of the Max Planck Society (MPG) from 1948 to 1960. He is famous for invention of atomic bomb.

Correct Option: A

Otto Hahn, (8 March 1879 – 28 July 1968) was a German chemist and Nobel laureate, a pioneer in the fields of radioactivity and radiochemistry. He is regarded as “the father of nuclear chemistry”. Hahn was a courageous opposer of Jewish persecution by the Nazi Party and after World War II he became a passionate campaigner against the use of nuclear energy as a weapon. He served as the last President of the Kaiser Wilhelm Society (KWG) in 1946 and as the founding President of the Max Planck Society (MPG) from 1948 to 1960. He is famous for invention of atomic bomb.