IGCSE Computer Science Paper-1: Specimen Questions with Answers 22 - 23 of 164

Question number: 22


Short Answer Question▾

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List the important purpose of the normalization in Database Management System.


Image of The Normal Forms

Image of the Normal Forms

The process of organizing the data into the database is known as Normalization.

i) It is used for dividing the larger table into the smaller tables thereby linking them using relationships.

ii) The normal forms 1NF, 2NF, 3NF and BCNF are used for reducing redundancy from the database table.

iii) The Normalization also helps in serving the process of insertion, deletion and updation of Anomalies.

iv) In Simple words Database Normalization is used for organizing non structured data in to structured data.

v) All data is stored only at one place and there is no redundancy of data.

Question number: 23


Appeared in Year: 2013

Short Answer Question▾

Write in Short

List the name of atleast one sensor that are used in Controlling a Central Heating System, Operation of Automatic Doors, Detection of Intruders, Monitoring of a greenhouse Environment.


A Sensor is a device that measures the physical property and records to ensure a better response to some type of input from the physical environment.

  • Controlling a Central Heating System: Thermostat is a sensor that is used in controlling a central heating system. It is a device that automatically regulates temperatures.

  • Operation of Automatic Doors: To operate automatic doors Optical sensors are used. These sensors are installed at the sides of the door to track motion. These automatic door sensors are used in industrial and commercial environments to allow easy access to a building, especially for disabled people.

  • Detection of Intruders: Fiber optic cable- sensors are used in the detection of intruders. These sensors are used to detect certain quantities such as mechanical strain or temperature, concentrations of chemical species, acceleration, rotations, pressure etc. These sensors are also used in remote sensing applications.

  • Monitoring of a greenhouse Environment: Moisture detection Sensors are used for measuring moisture content. For example level sensors will detect when CO2 goes above or below the critical threshold.

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