UGC NET EXPERTS- The Free Online Learning/Computer Science and Applications/All Topics A to Z

COMBINATIONAL CIRCUITS - Combinational circuits wo digital circuits hote hai jisme current input se hum output lete hain. Isme memory elements ko consider nahi kiya jata hai. Combinational Circuit mein kya output ayegi wo completely depend karti hai uski input values par. Basically the combinational circuits are as follows- Adders Subtractors Encoder Decoder Multiplexer Demultiplexer Combinational circuits ko design karne ke liye there are following steps- Problem ko clearly understand karna, Then, input and output variables ko find out karna, konsi input value hai and konsi output value hai. Then, input and output variables ko letters or symbols ki form mein assign karna. I/O symbols ko represent karne ke liye Truth Table create karna. Then, is truth table se boolean functions ko find karna. Ab boolean expressions ko solve karna with the help of K-Maps, or Boolean Algebra theorems. Then, finally draw diagram for the result. 1. ADDERS -  Adders means jab hum 2 binary numbers ko add k

Hello Dear Students, Hope you all are doing good. Today we will going to study about the logical circuits basic introduction. Let's get started... LOGICAL CIRCUITS - Basically logical gates connected hote hain, ek gate ki output doosre gate ki input hoti hai, then isko logical circuit kehte hain.  In digital systems, logical circuits are of 2 types- Combinational Circuits Sequential Circuits 1. COMBINATIONAL CIRCUITS -  In Combinational Circuits, the output is determined by the current input state only. Means, the output depends on inputs only, at a given point of time. Isme memory element ko consider nahi kiya jata. Combinational circuits ko design karne ke liye only Gates and Circulatory lines ko use kiya jata hai.  It is easy to design. The speed is fast. It is less expensive. Combinational Circuits examples are- Adders Subtractors Decoders Encoders Multiplexers Demultiplexers 2. SEQUENTIAL CIRCUITS -  In Sequential Circuits, the output is determined by current input state al

Hello Dear Students, Hope you all are doing good.. So, aaj hum computer system architecture mein logical gates ke baare mein study karenge, Let's get started... Boolean algebra has 3 operations basically, which are AND, OR, and NOT, it corresponds to the electronic circuit as AND, OR, and NOT Gates.  AND is represented as . OR is represented as + NOT is represented as ' AND, OR, and NOT Gates ki help se hum Boolean functions ke logical diagram ko design kar sakte hain.  Gates for designing logical cirucits Note that- NAND and NOR Gates are called Universal Gates , because other gates can be derived from NAND and NOR Gates, Other gates can be - AND, OR, NOT, XOR, XNOR.  Logical gates mein hum various inputs de sakte hain and it produces one output as function. For an example ,  Design a logical diagram for the function F=X'Y+XY'+Z' . So, the logical diagram of the above function F is as follows- Here, X' means complement of X, and so on. Here, ' means compl

Hello Dear Students, Hope you all are doing good... So, aaj hum boolean algebra topic ko cover karenge, Let's get started... BOOLEAN ALGEBRA - Boolean Algebra was first developed by George Boole in 1854, but the formal definition was given by E.V.Huntington in 1904. Boolean ka matlab hota hai true or false, here 0 and 1. Boolean Algebra is a branch of mathematics algebra. Boolean algebra is set of 3 operations which are- + (similar to logical OR), also denoted as ∨  ・(similar to logical AND), also denoted as ∧ ー (NOT), also denoted as prefix ᄀ There are only 2 values i.e. 0 and 1, agar hum koi bhi operation perform karenge so uska result 0 and 1 mein hi ayega, whether 0, 1, or combination of 0 and 1. The Truth Table of these 3 operations, AND, OR, NOT as as follows-  Truth Table for AND A  B  R  0  0  0  0  1  0  1  0  0  1  1  1  Truth Table for OR A  B  R  0  0  0  0  1  1  1  0  1  1  1  1  Truth Table for NOT A  R  0  1  1  0  PRECEDEN

Hello Dear Students, Hope you all are doing good. Aaj hum computer arithmetic ke baare mein study karenge, means computer mein kaise arithmetic perform hote hain, addition, subtraction, multiplication, division. Let's get started... As we all know, computer can only understand the binary language, means 0s and 1s. So, computer mein jab bhi operations perform kiye jate hain, wo binary form mein kiye jate hain.  Basically, the computer arithmetic deals with the method of representing fixed and floating-point numbers in digital systems. Computer arithmetic performs on binary numbers- Binary Addition Binary Subtraction Binary Multiplication Binary Division 1. BINARY ADDITION - Binary addition mein hum 0s and 1s hi lete hain, isme hum binary numbers mein addition operation perform karte hain. Binary addition perform karne ke liye 2 situations hoti hain, which are- Half Adder - Half Adder mein 2 input values hoti hain and 2 output values hoti hain. Full Adder - Full Adder mein 3 input v

Hello Dear Students, Hope you all are doing good. So, in previous lecture, we have studied about the number system, and now we will study about the conversions of number system. Let's get started... Ek number system ko doosre number system mein convert karne ke liye various conversions technique use ki jati hai. The possible types of conversions are as follows- Other Base System to Decimal Decimal to Other Base System Other Base System to Non-Decimal 1. OTHER BASE SYSTEM TO DECIMAL  - Binary number, octal number and hexadecimal number ko Decimal number mein convert karne ke liye following steps- Find place value of each digit, place value is the base of number system. Multiply the place value with their place holders. Find the sum of all products.  Number in any base  Conversion  Decimal Number   Binary Number (1010)         1*2 3 +0*2 2 +1*2 1 +0*2 0      =1*6+0*4+1*2+0*1 =6+0+2+0 =8   8  Octal Number(504) 5*8 2 +0*8 1 +4*8 0 =5*64+0*8+4*1 =320+0+4 =324   324 Hexadecimal Number(A6

Hello Dear Students, Hope you all are doing good.. Aaj hum computer number system ke baare mein study karenge, So, let's get started.... Computer system ki language Binary language hoti hai. Binary Language means 0s and 1s. User jo bhi input deta hai, computer usse binary form mein convert karke processing karta hai, because computer system can understand only 0s and 1s.  So, hum discuss karenge binary numbers ko. Decimal Number              Binary Number  Explanation    0     0  Since we take only 0 and 1, so first comes 0  1  1  Now, the next of 0 is 1, so here value of decimal no 1 is 1  2  10 After 1, there is 10 in which 0 and 1 comes, because from 2 to 9, there is no 0 and 1.   3  11 After 10, 11 has 0 or 1.which is 11.   4  100 After 11, there is only 100 which is 0 and 1s.  5  101  Next is 101,thus 5 is stored in computer as 101.  6  110  Next is 110,thus 6 is stored in computer as 110.  7  111  Next is 111, thus 7 stores in computer as 111.  8  1000  After 111, there comes

Hello Dear Students, Hope you all are doing good. So, after input and output peripheral devices, we will study about Memory peripheral devices. Let's get started... Peripheral devices wo devices hote hain jo ki system ke saath externally connect kiye jate hain so that computer se information li ja sake and computer ko information di ja sake.  MEMORY DEVICES -  Memory means storage space jisme sab kuch save kiya jata hai and store karaya jata hai. Jab user input devices se system ko input deta hai, then wo memory mein ja kar store ki jati hai. Then, wo input ko process kiya jata hai so that output can be produced. Their is a difference between memory and storage, Memory refers to the amount of RAM installed in the computer, and Storage refers to the capacity of computer hard disk. The various secondary storage devices are as follows- Magnetic Tape Magnetic Disk Floppy Disk Hard Disk CD-ROM 1. MAGNETIC TAPE -  Magnetic Tape basically data ko store karne ke liye use hoti hai. It is

Hello Dear Students, Hope you all are doing good.. During last lecture, we have study about the peripheral devices and input devices, now, Let's study about the Output devices... Peripheral Devices basically wo devices hote hain jo ki externally attach kiye jate hain system ke saath and computer ko data transfer karne ke liye use kiye jate hain. OUTPUT DEVICES -   Output devices wo device hote hain jiski help se computer hume output or result provide karta hai. So, Output devices are the inter-mediator between user and the computer. User data ko computer mein feed karta hai and computer ko instructions deta hai, computer usse process karne ke baad user ko output or result provide kar deta hai. Jis devices se computer user ko result provide karta hai, wo output devices hote hain. Output can be produced as a softcopy(that cannot be touched) or a hardcopy(that can be touched). The various output devices are as follows- Monitor Projector Printer Speaker Plotters MONITOR -  Monitor is

Hello Dear Students, Hope you all are doing good. Peripheral devices topic is most basic and important and is topic se questions mostly exam mein aate hain.  So, let's get started... PERIPHERAL DEVICES - Peripheral basically is piece of computer hardware which is added to host computer.  In simple words, peripheral devices wo devices hote hain jo ki externally computer se attach kiye jate hain and are optional basically, for example printer, scanner, USB, etc..  Monitors and disk drives are not considered as Peripheral devices because these devices are mandatory and not optional. However, video capture cards are sometimes not considered as Peripheral devices because they are added inside the computer. So, peripheral devices wo hote hain jo externally add kiye jate hain computer mein, such as WiFi cards. Basically peripheral devices wo devices hote hain jo ki computer ko information dene and computer se information lene mein kaam ate hain. Common Peripheral Devices are as follows-