scientist, discoveries & inventions MCQ section 4 MCQ Questions & Answers Detailed Explanation

Answer: (c)

A crescograph is a device for measuring growth in plants. It was invented in the early 20th century by Sir Jagadish Chandra Bose - an Indian polymath, physicist, biologist, botanist, and archaeologist.

Answer: (a)

Martin Cooper, an American engineer, conceived the first handheld mobile phone while at Motorola in 1973. He led the team that developed it and brought it to market in 1983. He is considered the “father of the cell phone” and is also cited as the first person in history to make a handheld cellular phone call in public.

Answer: (d)

Meteorology is the scientific study of the atmosphere or weather. Meteorological phenomena are observable weather events which are explained by the science of meteorology. Those events are bound by the variables that exist in Earth’s atmosphere; temperature, air pressure, water vapor, etc.

Answer: (d)

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 X-radiation to signify an unknown type of radiation.

Answer: (c)

Answer: (c)