In an E-R diagram, multivalued attributes are represented by-
- A.Rectangle
- B.Dashed ellipse
- C.Double ellipse
- D.Diamond
Correct answer
Explanation
The correct answer is C, Double ellipse. In an entity relationship diagram each symbol has a fixed meaning, and an attribute that can hold more than one value for the same entity, such as a person's several phone numbers, is drawn as a double ellipse. The standard set of symbols is worth memorising: a rectangle stands for an entity, a plain ellipse for an ordinary attribute, a diamond for a relationship, a double rectangle for a weak entity, a dashed ellipse for a derived attribute such as age worked out from date of birth, and an underlined attribute for the primary key. A is wrong because a rectangle marks an entity set. B is wrong because a dashed ellipse marks a derived attribute. D is wrong because a diamond marks a relationship between entities. Exam tip: rectangle entity, ellipse attribute, double ellipse multivalued, dashed ellipse derived, diamond relationship, underline key.
Practice Questions
View allWhich language uses the symbolic representation of machine codes needed to program a particular processor or processor family?
- A.Machine Language
- B.Assembly Language
- C.High-Level Language
- D.All of the above
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Assembly language replaces the binary machine codes of a processor with short symbols called mnemonics, such as MOV, ADD and JMP.
Read the full explanation →Which one of the following is the characteristic of Artificial Intelligence ?
- A.Replicates human decision making
- B.Stores relevant information
- C.Stores similar kind of data for a specific purpose
- D.Allows user to interact with media
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Read the full explanation →What is an interactive combination of text, graphics, video, audio and images termed as ?
- A.JPEG
- B.Multimedia
- C.AVA
- D.PNG
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Multimedia means using several forms of media, such as text, graphics, audio, video, images and animation, together, often in a way the user can interact with.
Read the full explanation →Which among the following is a malicious software?
- A.Hacking
- B.Password Cracking
- C.Trojan Horse
- D.Firewall
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A Trojan is a program that looks useful or harmless but secretly carries harmful code, so it is a piece of malicious software, or malware.
Read the full explanation →Which one of the following is not an application software?
- A.Spreadsheet
- B.AutoCAD
- C.MS PowerPoint
- D.Linker
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A linker is system software, a programming tool that joins compiled pieces of code into one program that can run; it does not do a task for the end user.
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