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

Answer: (d)

An optical fibre (or optical fibre) is a flexible, transparent fibre 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 fibre.

The field of applied science and engineering concerned with the design and application of optical fibres is known as fibre optics. Optical fibres are widely used in fibre-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 who invented optical fibre.

Answer: (d)

There are different methods of counting microbial growth. These are based on different parameters of cells such as dry-weight and wet-weight measurement, absorbance, cell plate, density, turbidity, ATP measurement, viable count, ATPase activity and use of Coulter counter. Absorbance is measured by using a spectrophotometer.

Cell growth of any bacterial suspension at a particular wavelength at different intervals is measured in terms of absorbance.

Answer: (d)

Answer: (d)

Answer: (c)

Gottlieb Daimler invented the prototype of the modern gasoline engine in 1885. This gas engine was made with a vertical cylinder, and gasoline injected through a carburetor (patented in 1887). Daimler first built a two-wheeled vehicle the "Reitwagen" (Riding Carriage) with this engine and a year later built the world's first four-wheeled motor vehicle.

Answer: (a)

A hygrometer is an instrument used for measuring the moisture content in the environment. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed.