Question Discussion & Solution

The correct answer is A thin layer of silicon.

Key Points

• In computers, the chip is made up of a thin layer of silicon.
  • Computer chips are made of silicon, which is a semiconductor, and in order to make the most efficient use of it, chip manufacturers use sand that contains as much silicon as possible.
  • The mineral quartz is ideal for this purpose because its two main components are silicon and oxygen.
  • Silicon is used because it can be used as either an insulator (doesn't allow electricity to flow) or a semiconductor (allows a little flow of electricity).
  • This is important for making chips.
  • It is very, very cheap.
• Hence, option 2 is correct. 

Additional Information

• Silicon is used for electronic devices because it is an element with very special properties.
  • One of its most important properties is that it is a semiconductor.
  • This means that it conducts electricity under some conditions and acts as an insulator under others.
  • It is even the most common element in the Earth's crust. 
• Lady Ada Lovelace invented looping in computer programming​.
  • Lady Ada Lovelace wrote a complete plan describing the algorithm needed to calculate the Bernoulli numbers using two loops, demonstrating the bifurcation capabilities of the analytical machine, describing how to perform trigonometric operations that made use of variables.

Concept:

The Android operating system was developed by Google for use in all of its touchscreen devices, tablets, and cell phones. This operating system was first developed by Android, Inc., a software company located in Silicon Valley before it was acquired by Google in 2005

The first public release of Android 1.0 occurred with the release of the T-Mobile G1 (aka HTC Dream) in October 2008. Android 1.0 and 1.1 were not released under specific code names.

Android name with their respective versions

Explanation:

Hygrometer:

• A hygrometer is an instrument used to measure the amount of water vapour in the air (humidity), in soil, or in confined spaces.
• Humidity measurement instruments usually rely on measurements of some other quantities such as -
  • Temperature, pressure, mass, a mechanical or electrical change in a substance as moisture is absorbed.

Additional Information

Hydrometer:

• A hydrometer is an instrument used for measuring the relative density of liquids based on the concept of buoyancy.
• They are typically calibrated and graduated with one or more scales such as specific gravity.
• Hydrometers can be divided into two general classes -
  • liquids heavier than water 
  • liquids lighter than water

A photometer is used to measure the intensity of light produced by an unknown source in terms of a standard source.

• It is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum.
• Most photometers convert light into an electric current using a photoresistor, photodiode, or photomultiplier.
• Photometers are used to determine the correct exposure in photography.
• Photometers measure Illuminance, Irradiance, Light absorption, Scattering of light, Reflection of light, Fluorescence, Phosphorescence and Luminescence.

An animal walked 29 m south.

From here it turned right and walked 14 m.

Now it again turned right and walked 18 m.

Now it turned left and walked 27 m.

Animal facing West now.

Hence, option 2 is the correct answer.