AS Computer Science/ Cyfrifadureg Progress Check 2

A university consists of a number of departments. Each department offers several courses. A number of modules make up each course. Students enrol on a particular course and take modules for that course.

Draw an entity relationship diagram to represent this situation.

1.     Give the simplest Boolean Expression for the truth table.

• C = B AND NOT A

• C = A NOT AND B

• C = A AND NOT B

• A = C NOT NOT B

1.     Give the simplest Boolean Expression for the truth table.

• a.       P = NOT ( R OR Q ) or R = NOT P AND NOT S

• a.       R = AND ( P OR Q ) or R = NOT P NOT NOT Q

• R = NOT ( P OR Q ) or R = NOT P AND NOT Q

• R = NOTT ( Q OR Q ) or R = NOT P AND NOT Q

Give the simplest Boolean Expression for the truth table.

• X = AND (X XOR Y)

• Z = NOT (X AND Y)

• Y = NOT (X XOR Z)

• Z = NOT (X XOR Y)

 

1.     Different primitive data types are used in computer systems.

a.     Using the denary example 108₁₀ calculate the minimum storage requirements for an integer data type within a range of 0₁₀ to 127₁₀.

Mathematical Equivalence

ON

a.    Convert 31₁₆ and 6D₁₆ into binary numbers and add them together using binary addition.

Mathematical Equivalence

OFF

a.    In a certain computer system, real numbers are stored in floating point form using two’s complementation, a 12-bit mantissa and a 4 bit exponent. Convert the number 16.125₁₀ into this floating-point form.

Mathematical Equivalence

ON

a.    In a certain computer system, real numbers are stored in floating point form using two’s complementation, an 8-bit mantissa and a 4-bit exponent.

 

The following is a floating-point representation of a real number.

Mantissa  Exponent

0 . 1 1 0 1 0 0 0 0 0 1 1

 

Calculate the denary value of the mantissa and exponent, and convert this floating-point number into a denary number.

Mathematical Equivalence

ON

1.     Clearly showing each step, simplify the following Boolean expression:

A . A ( A + C ) + C . ( A + B )

• 𝐴 + 𝐴. 𝐶 + 𝐶. 𝐵
  𝐴 + 𝐶. 𝐵

• 𝐴 + 𝐴. 𝐶 + 𝐴. 𝐶 + 𝐶. 𝐵

• 𝐴 + 𝐴. 𝐶 + 𝐶. 𝐴 + 𝐶. 𝐵

• 1.       A. (𝐴 + 𝐶) + 𝐶. (𝐴 + 𝐵)

• 𝐴. 𝐴 + 𝐴. 𝐶 + 𝐶. 𝐴 + 𝐶. 𝐵

 

State the use of the DHCP network protocol:

• Automatically assign IP addresses to devices on a network
• Encrypt data transmission on the network
• Control the speed of internet connection
• Manually assign IP addresses to devices on a network