scientist, discoveries & inventions MCQ section 3 MCQ Questions & Answers Detailed Explanation

Answer: (a)

Radar is an object detection system that uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.

The radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path.

In 1922 A. Hoyt Taylor and Leo C. Young, researchers working with the U.S. Navy invented Radar.

Answer: (a)

Sir Alexander Fleming discovered the world’s first antibiotic— benzylpenicillin (Penicillin G)—from the mould Penicillium notatum in 1928. For this discovery, he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain.

Answer: (c)

Ethology is the scientific and objective study of animal behavior, usually with a focus on behavior under natural conditions. The term was first popularized by American myrmecologist (the study of ants) William Morton Wheeler in 1902.

Answer: (d)

The connection between electricity and magnetism was discovered by famous Danish chemist and physicist, Hans Christian Oersted in 1819. Starting about a decade after Oersted’s discovery, Michael Faraday demonstrated essentially the opposite of what Oersted had found–that a changing magnetic field induces an electric current.

He achieved an electrical current from a changing magnetic field, a phenomenon known as electromagnetic induction. Following Faraday’s work, James Clerk Maxwell developed equations, formally unifying electricity and magnetism.

So it was Maxwell who formulated the relationship between electricity and magnetism.

Answer: (c)

The term “ecosystem” was first coined by Roy Clapham in 1930, but it was ecologist Arthur Tansley who fully defined the ecosystem concept.

In his classic article of 1935, Tansley defined ecosystems as “The whole system,… including not only the organism complex but also the whole complex of physical factors forming what we call the environment.”

Answer: (d)

Euclid, also known as Euclid of Alexandria, was a Greek mathematician, often referred to as the “Father of Geometry”. He was active in Alexandria during the reign of Ptolemy I (323–283 BC). Euclid deduced the principles of what is now called Euclidean geometry from a small set of axioms.

Euclid also wrote works on perspective, conic sections, spherical geometry, number theory and rigour. Although many of the results in Elements originated with earlier mathematicians, one of Euclid’s accomplishments was to present them in a single, logically coherent framework, making it easy to use and easy to reference, including a system of rigorous mathematical proofs that remains the basis of mathematics 23 centuries later.