Lesson 4 Number System-Other Binary Codes – Brihha Assessment Platform

1. Binary coded decimal is a combination of

Two binary digits

Three binary digits

Four binary digits

Five binary digits

2. The decimal number 10 is represented in its BCD form as

10100000

01010111

00010000

00101011

3. Add the two BCD numbers: 1001 + 0100 =

10101111

01010000

00010011

00101011

4. Carry out BCD subtraction for (68) – (61) using 10’s complement method.

a) 00000111

b) 01110000

c) 100000111

d) 011111000

5. Code is a symbolic representation of __________ information.

a) Continuous

b) Discrete

c) Analog

d) Both continuous and discrete

6. When numbers, letters or words are represented by a special group of
symbols, this process is called __________

a) Decoding

b) Encoding

c) Digitizing

d) Inverting

7. A three digit decimal number requires ________ for representation in the
conventional BCD format.

a) 3 bits

b) 6 bits

c) 12 bits

d) 24 bits

8. How many bits would be required to encode decimal numbers 0 to 9999 in
straight binary codes?

a) 12

b) 14

c) 16

d) 18

9. The excess-3 code for 597 is given by __________

a) 100011001010

b) 100010100111

c) 010110010111

d) 010110101101

10. The decimal equivalent of the excess-3 number 110010100011.01110101 is
_____________

a) 970.42

b) 1253.75

c) 861.75

d) 1132.87

11. Decode the following ASCII code:
a) 1001010
b) 1001111
c) 1001000
d) 1001110
e) 0100000
f) 1000100
g) 1001111
h) 1000101

12. Write your name in ASCII using an 8-bit code with the leftmost bit always
0. Include a space between names and a period after middle initials.

13. Show the value of all bits of a 16-bit register that hold the number
equivalent to decimal 125 in
(a) binary
(b) binary-coded octal
(c) binary-coded hexadecimal
(d) binary-coded decimal (BCD)

14. Represent decimal number 6530 in
(a) BCD
(b) excess-3 code
(c) 2421 code
(d) Binary number.

15. The Gray code is sometimes called a reflected code because the bit values
are reflected on both sides of any 2" value. For example, as shown in Table
4.2, the values of the three low-order bits are reflected over a line drawn
between 7 and 8. Using this property of the Gray code, obtain:
a. The Gray code numbers for 16 through 31.
b. The excess-3 Gray code for decimals 10 to 19 as a continuation of the list in
Table 4.3 in course content.

16. Use the 10 BCD digits with the even parity in the leftmost position (total
of five bits per digit). Repeat with an odd-parity bit.

17. Represent decimal 2698 in the 2421 code of Table 4.3. Complement all
bits of the coded number and show that the result in the 9's complement of
2698 in the 2421 code.