1) Base of hexadecimal number system? Answer : 16 2) Universal gate in digital logic? Answer : NAND 3) Memory type that is non-volatile? Answer : ROM 4) Basic building block of digital circuits? Answer : Gate 5) Device used for data storage in sequential circuits? Answer : Flip-flop 6) Architecture with shared memory for instructions and data? Answer : von Neumann 7) The smallest unit of data in computing? Answer : Bit 8) Unit that performs arithmetic operations in a CPU? Answer : ALU 9) Memory faster than main memory but smaller in size? Answer : Cache 10) System cycle that includes fetch, decode, and execute? Answer : Instruction 11) Type of circuit where output depends on present input only? Answer : Combinational 12) The binary equivalent of decimal 10? Answer : 1010 13) Memory used for high-speed temporary storage in a CPU? Answer : Register 14) Method of representing negative numbers in binary? Answer : Two's complement 15) Gate that inverts its input signal? Answer : NOT 16)
VARIABLES AND CONSTANTS
A variable is defined as a meaningful name given to a data storage location in the memory of computer. A variable, is used to refer to the address of the memory where the data is stored. C language has two basic kinds of variables.
Numeric Variables
Numeric variables are used to store the values of integer values or floating point values. Modifiers like short, long, signed, and unsigned can also be used along with numeric variables. The difference between signed and unsigned numeric variables is that signed variables can be negative or positive but unsigned variables can only be positive. Therefore, by using an unsigned variable we can develop the maximum positive range. When we neglect the signed/unsigned modifier, C language automatically makes it a signed variable. To assign an unsigned variable, the unsigned modifier must be explicitly added during the assignation of the variable.
Character Variables
Single characters enclosed within single quotes are called character variable. These characters should be from any of the character from the ASCII character set—letters (‘a’, ‘A’), numerals (‘2’), or special characters (‘&’).
Declaring Variables
Particularly to declare the data type of the variable followed by its name. The data type indicates what kind of values that the variable can store. Variable names should always be meaningful and must project the purpose of their usage in the program. In C, variable declaration always finish with a semi-colon. For example,
int emp_num;
float salary;
char grade;
double balance_amount;
unsigned short int acc_no;
In C, variables can be declared at any place in the program but two things must be kept in mind.First, variables should be declared before using it.Second, variables should be assigned closest to their first point of use so that the source code is easier to maintain.
Initializing Variables
we initialize variable with some value while declaring the variables . For example,
int emp_num = 7;
float salary = 9800.99
char grade = ‘A’;
double balance_amount = 100000000;
Constants
Constants are identifiers whose values do not change. At any time the values to variables can be changed, values of constants can never be changed. Constants are used to reveal fixed values
like the charge on an electron or pi so that their value does not get changed in the program even by mistake.
Declaring Constants
To reveal a constant, precede the normal variable declaration with const keyword and assign it a value.
const float pi = 3.14;