How many candidate keys are possible with the table?RollNo Name Mobile City 1 Arun 91 Delhi 2 Sanjay 92 Mumbai 3 Arun 93 Noida 4 Varun 94 Guwahati 5 Arti 95 Kolkata
| RollNo | Name | Mobile | City |
| 1 | Arun | 91 | Delhi |
| 2 | Sanjay | 92 | Mumbai |
| 3 | Arun | 93 | Noida |
| 4 | Varun | 94 | Guwahati |
| 5 | Arti | 95 | Kolkata |
- One
- Two
- Three
- Four
The Correct Option is B
Approach Solution - 1
In the provided table, we need to identify the number of candidate keys. A candidate key is defined as a minimal set of attributes that can uniquely identify a table record. Let's analyze the table:
| RollNo | Name | Mobile | City |
| 1 | Arun | 91 | Delhi |
| 2 | Sanjay | 92 | Mumbai |
| 3 | Arun | 93 | Noida |
| 4 | Varun | 94 | Guwahati |
| 5 | Arti | 95 | Kolkata |
Each 'RollNo' is unique for every student, hence it can be a candidate key.
Each 'Mobile' number is also unique, thus it can be a candidate key.
Considering this analysis, we have two candidate keys: 'RollNo' and 'Mobile'.
Therefore, the correct answer is: Two.
Approach Solution -2
A candidate key is a minimal set of attributes that uniquely identifies each tuple in a table.
In the given table:
Therefore, the candidate keys are RollNo and Mobile.
Thus, the answer is (2) Two.
Top CUET Computer Science Questions
- Which one of the following is not a built-in-exception in Python?
- The following five statements describe the methods used for file handling in Python. Choose an option that correctly sequences the definition of each.
(A) Method used to open a file.
(B) Method used to write the objects in a binary file.
(C) Method used to read data from a binary file.
(D) Method used to return an integer that specifies current position of the file object.
(E) Method used to position the file object at a particular position in a file.
Choose the correct answer from the options given below: - While opening a text file, the text editor translates :
- In Python, when open() method is applied in ‘<a>' mode, a file is opened in append mode. If the file does not exist, then :
- A table student has two text fields defined as below:
Name_1 varchar(20),
Name2 char(20)
If Name_1 stores value as ‘Ana' and Name2 stores value as ‘Anuj', then Name_1 will consume characters space and Name2 will consume characters space.
Top CUET Database Concepts Questions
- Match List-I with List-II:
List-I List-II (A) Controlled Data Sharing (I) Same data maintained in different places does not match (B) Data Isolation (II) Limited Access given to users (C) Data Dependence (III) There is no mapping between two files (D) Data Inconsistency (IV) If the structure of a file is changed, all the existing programs accessing that file
also need to be changed - Which of the following is called a database instance?
- Which of the statement(s) is/are True for the given question.
Data elements are: 7, 5, 17, 13, 9, 27, 31, 25, 35.
Hash Table Size: 7
Hash Function: H(I) = (Data element) mod (Hash Table Size)
Options:
(A) Element 27 will create collision.
(B) Element 25 will create collision.
(C) Element 35 will create collision.
(D) Element 31 will create collision.
Choose the correct answer from the options given below: - What is the primary difference between a database and a file system?
- A domain in a relational database refers to:
Top CUET Questions
Select the statements that are CORRECT regarding patterns of biodiversity.
(A) Species diversity increases as we move away from the equator towards the poles(B) The tropical Amazon rain forest in South America has the greatest biodiversity on earth.(C) There is more solar energy available in the temperate region than tropics.(D) Tropical environments are less seasonal relatively more constant and predictableWhich of the following hormone is not produced by placenta ?
- Individuals with karyotype of 44+XXY having overall masculine development with few feminine development like Gynaecomastia has _______ chromosomal disorder.
- Match List - I with List - II.Choose the correct answer from the options given below :
List - I
List - II
A Streptokinase I Blood-Cholestrol lowering agents B Cyclosporin II Clot Buster C Statins III Propionibacterium sharmanii D Swiss Cheese IV Immuno suppressive agent Which of the following option determines percolation and water holding capacity of soils ?