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CHAPTER, , (1), , Number System, 2 MARKS QUESTIONS, , Q.1. Define digital signal., Ans. A, , [HSBTE-2017], digital signal is defined as the signal which has only a finite number of distinct values., , They have discrete value., , Q.2. Write the base of binary number system., , Ans. Base of binary number system is 2., , Q.3. Define Radix in number system., , HSBTE-2018], [HSBTE-2017], , Ans. It is defined as the number of different digits which can occur in each position in the, number system., , Q.4. Define a Byte., Ans. A byte is equal to 8 bits., , Q.5. Convert (23) 10 to binary., Ans. 2, , 23, , [HSBTE-2016], , (23)10 (10111), Ans., , 2 11-1, , 2 5-1, 2, , 2-1, , 2, , 1-0, , 0-1, Q.6. Convert decimal number 32 to binary., , Ans., , 2, , 32, , 2 16-0, , 2, 2, , (32)10 (100000). Ans., , 8-0, 4-0, , 2 2-0, 2 1-0, , 0-1, 1, , HSBTE-2016]
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Digital Electronics, , Q.7. Convert binary number (11. 0101) into decimal equivalent., , Ans., , 0101, = 1x2, , + 1+20 + 0 x 2-1+ 1 2-1 + 0x 2 + 1 x 2-4, 53, , =2+1+0+0+ t6=3 + i, , 16 =(3.3125)10, , 16, , [HSBTE-2015], , Q8. Convert (110 110 101), to octal., Ans., , HSBTE-2014, , 100 110 101, Each 3 bit group is converted to an octal digit., (110 110 101), =, , (665), , [HSBTE-2015, , Q.9. The radix ofoctal nunmber is., Ans. 8., , (HSBTE-2015, , Q.10. Define is complement method., Ans. l's complement of a number is found by converting l's to 0's and 0's to l's., , [HSBTE-2014, , Q.11. What is ?'s complement of 11001 ?, Ans. (11001),, l's complement =, , 0, , 0, , 1, , 1, , 2's complement =, , 0, , 0, , 1, , 1, , 0, , [HSBTE-2013, , Q.12. Subtract 0101 from 1101., Ans., , 1 1 0 1, -01 0 1, 10 0 0, , Ans., , Q.13. Convert (2A3C)1 to binary., , HSBTE-2013, , Ans., , 2, , 3, , 0010 1010 0011, , 1100, , 4bits combination, , (2A3C)16, , (0010 1010 0011 1100), , Q.14.Add 10010 and 11011., Ans., , [HSBTE-201, , (1), , (1), 10 0 1 0, , +1, , 1 0, , 1, , 1, , 10 1 1 0 1, , (101101)2, , Ans.
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Number System, , .15., Ans., , Define a, , Nibble, , 18 a, , Nibble., group of 4 bits., , Q.16. What, , is ASCIl code ?, , Q17. Write, , full form of BCD., , [HSBTE-2015], , ASCIl is American Standard code for Information interchange. lt represent ext, eomputers, telecommunication equipment and other devices., , [HSBTE-2018, , Ans. BCD is the Binary Coded Decimal., , QA8.Write 2's complement of 100000., Ans., , l's, , complement, , 2's, , complement, , 0, , 1, , 1, , 1, , 1, , 0, , 0, , 0, , =, , 1, , 1, , +1, =, , 0, , 0, , 19. (FF),16+ (1)16?, Ans., (F)16, , FF)16, , 11 1 1 1 1 1 1, , (1)16, , +1, 0 0 0, , 1, , 0, , 0, , 0 0, , 0, , = (100) 16 Ans, , 4 MARKSQUESTION, Q.1. Convert each of the following to decimal number, , (a) (AB9)16, , [HSBTE-2017], , (b) (140), , Ans. (a) (AB9)16, = 10x 102 + 162 x 12 +160 x 9, , 2560 + 192 +9, (2761) jo Ans., 6) (140)8, =, , = 1 x 82 + 4 x 8! + 0 x 80, , = 64, , 32 + 10, , = (96)]0, , Ans., , 9.2. Convert binary to decimal [HSBTE-2018)], (a) (1010.10)2 (b) (1111),, Ans. (a), (1010.10)2, =1 x 23 +0 x 22 + 1x 21 +0 x 20+ 1 x 2-1, , =8+0+2+0++0 =10+, (6), , (1111)2, = 1 x 23 +1x 22 + 1x 21 + 1 x 20, =8+4+ 2 +1+ (15)10, , Ans., , =, , +0, , x, , 2-2, , (10.5)10, , Ans.
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Digital Electronics, , Q.3., , Perform the required operation:, (a) 101010, , 1010, , (b) 1101 x 110, , Ans. (a), , 1 0 1 0 10, 0, , 0 0 0 0, , Ans., , 11 0, 0, , 0, , (1)1 1, , 0, , 1, , 1, , xx, , 1, , 10, , 1, , 10, , 1 001, Q.1., , Perform, , to, , 0, , 0, , Ans., , following operations, , (a) (122.15)10 = (Z), Find Z., , HSBTE-2015, , (b) (1100)- (1010), Ans. (a), , (122.15)10, 8, , 122, , S15-2, 81-7, , (122)10 (172)g, , 0-1, 0.15 x 8 = 1.20, , 1, , 0.20x 8= 1.60, , 1, , 0.60x 8z 4.80, , 4, , 0.80 x 8 = 6.40 6, (122.15)10 = (172.1146), , 100, , (b), , - 10 1, , 0, , 0 0 1 0, , Ans., , Q.5. Perform (10)- (15)10 using 2's complement method., Ans. Obtain 2's complement of (15), 10, , (15)10 (1111),, , l's, , complement=, , 0 0 0 0, , 2's, , complement, , 0 0 0, , 1, , [HSBTE-201
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5, , e r, S y s t e m, , ow add (10) and 2's complement of (15 10, , (10),= 1 0 1 0, 0, , 0, , 0, , 1, , 1, , 0, , 1, , 1, , 2's complement =, a, , carry so result in 2s complement from and negative., 1's complement =, , 0, , 2's, , 0, , 1, , 0, , 0, , +, , complement, , =, , 0, , 1, , 1, , Ans, , Find the addition using 2's complement method 10110010 and 10111000., , Ans., , Find, , [HSBTE-2017], , the 2's complement of 10111000, 1'scomplement = 0 1 0, , 0, , 0, , 1, , 0, , 1, , 0, , 1, , 1, , +1, 2's complement =, , 0, , 1, , 0, , 0, , 0, , Now. add the numbers, , 10 1 1 0 0 1 0, +0, , 1, , 0, , 0, , 1, , 11 1 1, , 0, , 0, , 0, , 1 01 0, , No carry so result in 2's complement from and negative., , l's complement = 0 0 0 0 0 10 1, , So,, , +, , 2's complement =, , 0, , 0, , 0, , 0, , 1, , 0 11 0, , Ans., , [HSBTE-2016], , 7 . Subtract (11001), from (11101), using 2's complement., Ans. Find the 2's, , complement of (11001), l's complement =, , 0, , 0, , 1, , 10, +, , 2's complement, , 1, , 1, , 11 1 0, , 1, , 0, , =, , 0, , 1, , Now, add the numbers,, , 0, discard carry1, Final carry 1 indicates that the, , So, , (11101),, , -, , (11001),, , =, , 0 1 11, 0, , 0, , 10, , 0, , is positive and is its, (00100)2 Ans., answer, , true, , form., , 10 MARKS QUESTIONS, , 1.Briefny describe various types of number systems., s.There are four types of number systems, , ), , Decimal number systém., , [HSBTE-2016]
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Digital Electronics, , (ii) Binary number system, (iii) Octal number system, (iu) Hexadecimal number system, contains, (i) Decimal Number System: The decimal number system, The largest value of digit is 9., symbols: 0, 1,2,3, 4, 5, 6, 7, 8, 9. So, it has base of 10., a r e also called as weighted, represents a different multiple of 10. These multiples, weighted values of each position are as shown in figure., , an, , unique, place, , Each, , value., , The, , Decimal Point, , 101010|101010, is a system that u s e s only the, (ii) Binary Number System: The Binary number system, of the computer system u s e the binary logic for, digits '0 and l ' as codes. It u s e s the base 2. Most, for a binary system are as shown in, their operation. The weighted values for different positions, , figure:, , ::|;FFF=Binary point, , (iii) Octal, value ofa, , The, It has eight digits from 0 to 7. It has a base, octal system is 7. Each digits has a different multiple of base., , Number, , digit in a, , of 8., , System:, , largest, , -, , Octal Point, , (iv) Hexadecimal Number System: It has a base of 16 which requires sixteen digits. The, also, digits used are 0 to 9 and A to F. In this system numbers and letters are used so this is, called alphanumeric number system. The positional weight for a hexadecimal number system, showas:, -, , Hex point, , Q.2., , Write short, , note, , on, , ASCII code., , [HSBTE-2018), , 1s. ASCI Code: This known as American Standard code for Information Interchange. The, ASCII code is 7 bit code and can present 2"= 128 possible characters. This 7 bit code is used, represent all the standard keyboard characters as well as control functions. Every tim- a keyi8, denressed on ASCII keyboard, the key is converted into ASCII code and processed by compd, Thus before outputting the computer contents to monitor or printer, all information is conver, me, , er., , from ASCII to standard English alphabet., OO0
