Question 1

Question 1(i)Which of the following is/are principle(s) of Object Oriented Programming?EncapsulationAbstractionInheritanceAll of these

Accepted Answer

All of theseReason — Encapsulation, abstraction and inheritance are principles of Object Oriented Programming.

Question 2

Question 1(ii)If a = 8 and b = 4, the value of a % = b is2048

Accepted Answer

0Reason — The expression a % = b is evaluated as follows:a % = b⟹ a = a % b⟹ a = 8 % 4⟹ a = 0

Question 3

Question 1(iii)Predict the output of the following code snippet:int a = 1;
int b = 2;
if  (a == b)
    System.out.println("Both values are equal");
else 
    System.out.println("Values are not equal");Both values are equalIncorrect use of the == operatorValues are not equalNo output

Accepted Answer

Values are not equalReason — Since the values of a and b are not equal, the condition (a == b) is false. Thus, the else block is executed and "Values are not equal" is printed.

Question 4

Question 1(iv)Which of the following is mandatory in the switch statement?breakcontinuecasedefault

Accepted Answer

caseReason — The keyword 'case' is mandatory in the switch statement.

Question 5

Question 1(v)Which of the following is not a valid method of the Scanner class?next( )nextInt( )nextLong( )nextNumber( )

Accepted Answer

nextNumber( )Reason — nextNumber( ) is not a valid method of the Scanner class.

Question 6

Question 1(vi)What will be the output of Math.floor(-20.10);?-20.0-21.02021

Accepted Answer

-21.0Reason — Math.floor() method returns the largest double value that is less than or equal to the argument and is equal to a mathematical integer. Thus, -21.0 is returned by Math.floor(-20.10); method.

Question 7

Question 1(vii)Which of the following is an illegal identifier?age123abc_value$	ext{	extdollar}$salary

Accepted Answer

123abcReason — 123abc is not a valid identifier because it starts with a number, which is not allowed.

Question 8

Question 1(viii)Which of the following is/are jump statement used in Java?breakcontinuereturnAll of these

Accepted Answer

All of theseReason — break, continue and return are jump statements used in Java.

Question 9

Question 1(ix)Class initialisation is the ............... initialisation of class fields of values.explicitimplicitBoth a and bNone of the above

Accepted Answer

explicitReason — Explicit class initialisation is the initialisation of class fields of values.

Question 10

Question 1(x)Operations like square root, sine and cosine areimpure functionspure functionsstatic functionsclass functions

Accepted Answer

pure functionsReason — Operations like square root, sine and cosine are pure functions as they do not modify their arguments.

Question 11

Question 1(xi)Given array int x[ ] = {11, 22, 33, 44}; the value of x[1 + 2] is :11223344

Accepted Answer

44Reason — Array index starts from 0 to Size - 1. The value of x[1 + 2] equals x[3]. The value at index 3 is 44.

Question 12

Question 1(xii)A linear searchcan be used with sorted arrays only.can be used with unsorted arrays only.can be used with both sorted and unsorted arrays.cannot be used with arrays.

Accepted Answer

can be used with both sorted and unsorted arrays.Reason — A linear search can be used with both sorted and unsorted arrays.

Question 13

Question 1(xiii)Method that converts a character to uppercase istoUpper()ToUpperCase()TOUPPERCASE()toUpperCase(char)

Accepted Answer

toUpperCase(char)Reason — Method that converts a character to uppercase is toUpperCase(char).

Question 14

Question 1(xiv)Give the output of the following codeSystem.out.println("Good".concat("Day"));GoodDayGood DayGooddaygoodDay

Accepted Answer

GoodDayReason — concat() method will add "Day" at the end of "Good" and "GoodDay" will be printed on the screen.

Question 15

Question 1(xv)The array char arr[8] occupies :3281624

Accepted Answer

16Reason — char datatype requires 2 bytes of memory. 8 char type elements will require 2 x 8 = 16 bytes of memory.

Question 16

Question 1(xvi)This access specifier achieves the lowest level of accessibility.PublicProtectedPrivateDefault

Accepted Answer

PrivateReason — Private access specifier achieves the lowest level of accessibility as a data member or member method declared as private is only accessible inside the class in which it is declared.

Question 17

Question 1(xvii)Assertion (A) Line comment is used for a single line of comment.Reason (R) A line comment starts with forward slash and asterisk(/*).Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).Both Assertion (A) and Reason (R) are true and Reason (R) is not a correct explanation of Assertion (A).Assertion (A) is true and Reason (R) is false.Assertion (A) is false and Reason (R) is true.

Accepted Answer

Assertion (A) is true and Reason (R) is false.Reason — Assertion (A) is true as a line comment is used for a single line of comment. Reason (R) is false as a line comment starts with two forward slashes (//).

Question 18

Question 1(xviii)Read the following text and choose the correct answer:Byte streams are used to perform input and output of 8-bytes. They are used to read bytes from the input stream and write bytes to the output stream. Mostly, they are used to read or write raw binary data.Which of these class is used to read and write bytes in a file?FileReaderFileWriterFileInputStreamInputStreamReader

Accepted Answer

FileInputStreamReason — FileInputStream class is used to read and write bytes in a file.

Question 19

Question 1(xix)Assertion (A) The private access specifier achieves the lowest level of accessibility.Reason (R) The private methods and fields can be accessed only within the same class to which the methods and fields belong.Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).Both Assertion (A) and Reason (R) are true and Reason (R) is not a correct explanation of Assertion (A).Assertion (A) is true and Reason (R) is false.Assertion (A) is false and Reason (R) is true.

Accepted Answer

Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).Reason — Both Assertion (A) is true as private access specifier achieves the lowest level of accessibility and Reason (R) explains Assertion (A) correctly as a data member or member method declared as private is only accessible inside the class in which it is declared.

Question 20

Question 1(xx)State the data type after the following is executed :char ch = '9';
res = Character.isDigit(ch);intcharstringboolean

Accepted Answer

booleanReason — isDigit() method returns true if the specified character is a digit; returns false otherwise. Thus, the return type is boolean.

Solved Sample Paper 4