Name: Class: Date: MECH 1500 Quiz 2 Review True/False Indicate whether the statement is true or false. 1. The decimal system uses the number 9 as its base. 2. All digital computing devices perform operations in binary. 3. The base of a number system determines the total number of unique symbols used by that system. 4. In any number system, the position of a digit that represents part of the number has a weighted value associated with it. 5. Usually a group of 8 bits is a byte, and a group of one or more bytes is a word. 6. To express a number in binary requires fewer digits than in the decimal system. 7. In the Gray code there is a maximum of one bit change between two consecutive numbers. 8. Binary number systems use positive and negative symbols to represent the polarity of a number. 9. Normally, a binary 1 represents the presence of a signal, while a binary 0 represents the absence of a signal. 10. All inputs to an AND gate must be 1 to produce a 1 output. 11. All inputs to a NAND gate must be 1 to produce a 1 output. 12. Only one input to an OR gate must be 1 to produce a 1 output. 13. All inputs to a NOR gate must be 1 to produce a 1 output. 1
Name: 14. The AND function, implemented using switches, will mean switches connected in parallel. 15. A two input OR function, expressed as a Boolean equation, would be Y= AB. 16. Hardwired logic is fixed and is changeable only by altering the way devices are connected. 17. Programmable control is based on logic functions that are programmable and easily changed. 18. There is no difference between a relay schematic and a ladder logic program. 19. One of the most common PLC programming languages is ladder logic. 20. Ladder logic is a graphical representation of a user program. Multiple Choice Identify the choice that best completes the statement or answers the question. 21. In any number system, the position of a digit that represents part of the number has a "weight" associated with its value. The place weights for binary: a. start with 1 and are successive powers of 2. b. increase by adding 2 for each place, starting with 0. c. increase by adding 2 for each place, starting with 2. d. start with 2 and double for each successive place. 22. The number 12 is: a. 12 in any number system. c. 12 in binary. b. 12 in decimal. d. all of the above. 23. The octal number 153 would be written in binary as: a. 011 101 001. c. 011 111 101. b. 001 101 011. d. 010 100 011. 2
Name: 24. The decimal number 28 would be written in binary as: a. 11100. c. 10110. b. 00111. d. 01011. 25. 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. 26. One byte of the data shown is represented by: a. No. 1 c. No. 3 b. No. 2 d. No. 4 27. The MSB of the data shown in Figure 3-1 is represented by: a. No. 1 c. No. 3 b. No. 2 d. No. 4 28. The acronym BCD stands for: a. binary-coded decimal. c. base code decoder. b. binary code decoder. d. base-coded decimal. 29. For a base 8 number system, the weight value associated with the third digit would be: a. 16. c. 64. b. 32. d. 512. 3
Name: 30. In the sign bit position, a 1 indicates a(n): a. negative number. c. octal code. b. positive number. d. hexadecimal code. 31. 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. 32. A(n) d. both a and b bit is used to detect errors that may occur while a word is moved. a. parity c. positive b. negative d. overflow 33. The binary concept makes use of the fact that certain informal a. can exist in one of two possible states. b. can be broken down into smaller units for easier analysis. c. can be divided into two or more categories. d. can be divided into two, or multiples of two, categories. 34. The basic rule for an AND gate is: a. if all inputs are 1, the output will be 1. b. if all inputs are 1, the output will be 0. c. if all inputs are 0, the output will be 1. d. both a and b. 35. 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. 36. The NOT function can be thought of as: a. a FALSE-to-TRUE converter. c. an inverter. b. a changer of states. d. all of these. 4
Name: 37. With reference to the logic circuit, the output Y will be at a logic 1 when: a. inputs A and B are logic 1. b. input A or B is logic 1. c. input A is at logic 1 and input B is at logic 0. d. input A is at logic 0 and input B is at logic 1. 38. The logic symbol drawn in that of the: a. AND function. c. NOR function. b. OR function. d. NAND function. 39. The Boolean equation for the logic symbol is: a. A = Y c. b. A=B d. 40. The Boolean expression for the logic circuit drawn in is: a. Y = (A B)(CD) c. b. d. Y= ABC + D 5
Name: 41. Which logic circuit represents the Boolean expression Y = A(BC+D)? a. (a) c. (c) b. (b) d. (d) 42. Which of the hardwired relay schematics of is being implemented by the PLC program shown? a. (a) c. (c) b. (b) d. (d) 6
Name: 43. A OR gate operates on the same principle as: a. a series circuit. c. a series-parallel circuit. b. a parallel circuit. d. none of these. 44. A NOR gate is: a. an AND gate with an inverter connected to the output. b. an OR gate with an inverter connected to the output. c. equivalent to a series circuit. d. equivalent to a parallel circuit. 45. If you want to know when one or both matching bits in two different words are ON, you would use the logic instruction. a. AND c. OR b. XOR d. NOT Short Answer 46. Convert the binary number to a decimal number: 1111110 47. Convert the binary number to a decimal number: 10000000 48. Convert the decimal number to a binary number: 20 49. Convert the decimal number to a binary number: 17 50. Convert the Octal number to a binary number: 74 51. Convert the decimal number to BCD: 99 52. What is the 1s complement of 1001101? 53. Simplify, answer must be in binary. 100 +101 7
Name: 54. Simplify, answer must be in binary. 1110-0111 55. Answer must be in binary. 100 x 101 56. Answer must be in binary. 10100 10 8
MECH 1500 Quiz 2 Review Answer Section TRUE/FALSE 1. ANS: F 2. ANS: T 3. ANS: T 4. ANS: T 5. ANS: T 6. ANS: F 7. ANS: T 8. ANS: F 9. ANS: T 10. ANS: T 11. ANS: F 12. ANS: T 13. ANS: F 14. ANS: F 15. ANS: F 16. ANS: T 17. ANS: T 18. ANS: F 19. ANS: T 20. ANS: T MULTIPLE CHOICE 21. ANS: A 22. ANS: B 23. ANS: B 24. ANS: A 25. ANS: A 26. ANS: A 27. ANS: B 28. ANS: A 29. ANS: C 30. ANS: A 31. ANS: C 32. ANS: A 33. ANS: A 34. ANS: A 35. ANS: A 36. ANS: D 1
37. ANS: C 38. ANS: D 39. ANS: D 40. ANS: B 41. ANS: A 42. ANS: B 43. ANS: B 44. ANS: B 45. ANS: C SHORT ANSWER 46. ANS: 126 47. ANS: 128 48. ANS: 10100 49. ANS: 10001 50. ANS: 111100 51. ANS: 1001 1001 52. ANS: 0110010 53. ANS: 1001 2
54. ANS: 0111 55. ANS: 10100 56. ANS: 1010 3