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Class 12

Information Technology (802)

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241

Which method of the Statement object is used to execute a SELECT query and returns a ResultSet?

MCQ Medium

a. executeUpdate()

b. executeQuery()

c. runQuery()

d. fetch()

Information Technology (802) · Class 12 · Sep 26, 2026

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executeQuery()

Explanation: The executeQuery(query) method executes a SELECT SQL statement and returns a ResultSet object containing the results.

242

What is a key limitation of using the DBMS approach?

MCQ Medium

a. It cannot store large volumes of data

b. High cost of implementation and security/recovery overheads

c. It does not allow multiple users

d. It cannot be used for small databases

Information Technology (802) · Class 12 · Sep 26, 2026

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High cost of implementation and security/recovery overheads

Explanation: The DBMS approach has a high implementation cost and involves security/recovery overheads (e.g., regular backups), making it less preferred for small, simple databases.

243

A ResultSet object represents:

MCQ Medium

a. A single row of data

b. A table of data returned by an SQL query

c. The database connection itself

d. An exception object

Information Technology (802) · Class 12 · Sep 26, 2026

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A table of data returned by an SQL query

Explanation: A ResultSet is a table of data (rows and columns) returned by executing an SQL query via executeQuery().

244

The relational database model was developed by:

MCQ Medium

a. Charles Babbage

b. E.F. Codd

c. Dennis Ritchie

d. James Gosling

Information Technology (802) · Class 12 · Sep 26, 2026

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E.F. Codd

Explanation: The relational database model was developed by E.F. Codd at IBM in 1970.

245

Which method of the ResultSet object is used to move to the next row and returns false when there are no more rows?

MCQ Medium

a. hasNext()

b. next()

c. getNext()

d. moveNext()

Information Technology (802) · Class 12 · Sep 26, 2026

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next()

Explanation: The next() method of ResultSet moves the cursor to the next row and returns false when there are no more rows left.

246

In the relational model, a row of a table is called a:

MCQ Easy

a. Domain

b. Attribute

c. Tuple

d. Relation

Information Technology (802) · Class 12 · Sep 26, 2026

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Tuple

Explanation: In relational model terminology, a row is called a Tuple, a column is an Attribute, and a table is a Relation.

247

Which type of exception is typically thrown by database connectivity operations, requiring a try-catch block?

MCQ Medium

a. ArithmeticException

b. SQLException

c. NullPointerException

d. ArrayIndexOutOfBoundsException

Information Technology (802) · Class 12 · Sep 26, 2026

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SQLException

Explanation: Database connectivity operations can throw an SQLException, so they should be enclosed in a try-catch block.

248

In the relational model, the number of attributes in a relation is called its:

MCQ Easy

a. Cardinality

b. Degree

c. Domain

d. Schema

Information Technology (802) · Class 12 · Sep 26, 2026

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Degree

Explanation: The Degree of a relation is the number of attributes (columns) it has; Cardinality is the number of tuples (rows).

249

If the try block does not throw any exception, the catch clauses following it are still executed.

TRUE FALSE Medium

a. TRUE

b. FALSE

Information Technology (802) · Class 12 · Sep 26, 2026

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FALSE

Explanation: If no exception is thrown, the catch clauses are NOT executed; program execution continues after the last catch clause.

250

In the relational model, the number of tuples in a relation is called its:

MCQ Easy

a. Degree

b. Domain

c. Cardinality

d. Attribute

Information Technology (802) · Class 12 · Sep 26, 2026

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Cardinality

Explanation: Cardinality of a relation is the number of rows (tuples) it contains.

251

The finally block is optional in a try-catch structure.

TRUE FALSE Medium

a. TRUE

b. FALSE

Information Technology (802) · Class 12 · Sep 26, 2026

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TRUE

Explanation: The finally block is optional; it is commonly used for cleanup code that should run regardless of whether an exception occurred.

252

The set of all possible values that an attribute may contain is called its:

MCQ Easy

a. Degree

b. Cardinality

c. Domain

d. Tuple

Information Technology (802) · Class 12 · Sep 26, 2026

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Domain

Explanation: The Domain of an attribute is the set of all atomic (indivisible) values that attribute may take.

253

How are exceptions handled in Java? Name the key keywords involved.

SHORT Medium

Information Technology (802) · Class 12 · Sep 26, 2026

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Explanation: Exceptions in Java are handled using try, catch, and (optionally) finally blocks. The try block surrounds code that might throw an exception; the catch block(s) handle specific exception types; the optional finally block always executes when the try block exits.

254

Which of the following is a characteristic of relations in the relational model?

MCQ Medium

a. Ordering of tuples is significant

b. No two tuples in a relation can be identical

c. Attribute values can be non-atomic (divisible)

d. Ordering of attributes must be maintained

Information Technology (802) · Class 12 · Sep 26, 2026

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No two tuples in a relation can be identical

Explanation: No two tuples of a relation should be identical; ordering of tuples and attributes is not significant, and attribute values must be atomic.

255

Write a Java code fragment demonstrating exception handling for a division by zero, using a divide() method that takes two integer parameters.

LONG Medium

Information Technology (802) · Class 12 · Sep 26, 2026

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Explanation: int divide(int dividend, int divisor) { return dividend/divisor; } ... try { int quotient = divide(10,0); System.out.println(quotient); } catch (Exception e) { System.out.println(e.getMessage()); }

256

A special value used to represent an attribute value that is unknown, not applicable, or unavailable is called:

MCQ Easy

a. Zero

b. Blank

c. NULL

d. Undefined

Information Technology (802) · Class 12 · Sep 26, 2026

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NULL

Explanation: NULL is used to represent an attribute value that is unknown, not applicable, or unavailable.

257

An assertion in Java is used to:

MCQ Medium

a. Improve runtime performance

b. Identify/detect and correct logical errors by checking that a condition is true at a certain point

c. Handle file input/output

d. Establish database connections

Information Technology (802) · Class 12 · Sep 26, 2026

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Identify/detect and correct logical errors by checking that a condition is true at a certain point

Explanation: An assertion is a mechanism to detect logical errors by checking that a stated condition should be true at a particular point during execution.

258

A Relational DBMS (RDBMS) is a DBMS that is:

MCQ Easy

a. Based on hierarchical data structures

b. Based on the relational model

c. Only used for spreadsheets

d. Not capable of storing numeric data

Information Technology (802) · Class 12 · Sep 26, 2026

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Based on the relational model

Explanation: An RDBMS is a DBMS based on the relational model, e.g., Oracle, MySQL, IBM DB2.

259

Which type of error is thrown when an assertion's expression evaluates to false?

MCQ Medium

a. ArithmeticException

b. AssertionError

c. SQLException

d. NullPointerException

Information Technology (802) · Class 12 · Sep 26, 2026

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AssertionError

Explanation: If the asserted expression is false, an AssertionError is thrown (with an optional custom error message).

260

A set of attributes in a relation for which no two tuples have the same combination of values is called a:

MCQ Medium

a. Candidate key

b. Primary key

c. Superkey

d. Foreign key

Information Technology (802) · Class 12 · Sep 26, 2026

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Superkey

Explanation: A Superkey is a set of attributes for which no two tuples in a relation state have the same combination of values; every relation has at least one (the set of all attributes).