1. Which of the following number systems has a base of 16?

a) Hexadecimal c) Binary-coded decimal

b) Octal d) Gray code

2. The number 12 is:

a) 12 in any number system. c) 12 in binary.

b) 12 in decimal. d) all of the above.

3. The decimal number 15 would be written in binary as:

a) 1111. c) 4C.

b) 1000. d) 00011001.

4. The octal number 62 would be written in decimal as:

a) A12. c) 50.

b) F35. d) 98.

5. The hexadecimal number 2D9 would be written in binary as:

a) 0010 1101 1001. c) 1100 1111 0010.

b) 1001 1011 0010. d) 0010 1011 1001.

6. The main advantage of using the Gray code is:

a) only one digit changes as the number increases.

b) it can be easily converted to decimal numbers.

c) large decimal numbers can be written using fewer digits.

d) it uses the number 2 as its base.

7. All digital computing devices operate using the

binary number system because:

a) most people are familiar with it.

b) large decimal numbers can be represented in a shorter form.

c) digital circuits can be easily distinguished between two voltage levels

d) all of the above.

8. The 2's complement form of a binary number is

the binary number that results when:

a) all the l's are changed to 0's.

b) all the 0's are changed to 1's.

c) 1 is added to the 1's complement.

d) both a and b

9. The ASCII code:

a) is used with absolute encoders.

b) is considered to be an error-minimizing code.

c) includes letters as well as numbers.

d) all of the above.

10. A(n)____________ bit is used to detect errors that may

occur while a word is moved.

a) parity c) positive

b) negative d) overflow

11. The basic rule for an OR gate is:

a) if one or more inputs are 1, the output is 1.

b) if one or more inputs are 1, output is 0.

c) if one or more inputs are 0, the output is 1.

d) both band c.

12. The OR function, implemented using contacts, requires contacts

connected in:

a) series c) series/parallel

b) parallel d) parallel/series