Exam Revision Questions Quiz SDD CS

Name the bus used to transfer instructions from the main memory to the processor.

Name the bus used to select memory locations for reading from or writing to.

Name the part of the processor that deals with comparisons.

• Registers

• ALU

  Arithmetic & Logic Unit

• Control Unit

• Buses

Name the part of the processor that temporarily stores values while they are being processed.

A computer program has the lines of code as shown:

Explain how the result will be calculated when line 3 is executed.

Answer explanation

variable wins is assigned the value 5

& variable points is assigned the value 3

(1 mark)

wins is multiplied by points, 5 x 3 = 15, and this value is assigned to total

(1 mark)

Must discuss contents of variables as well as operations to get 2 marks

A computer program has the following lines of code:

Explain how the result will be calculated when line 3 is executed.

Answer explanation

Variable size is assigned the value 5 &

variable named height is assigned the value 3

(1 mark)

size to the power of height, 5³ = 125, and this value is assigned to variable result

(1 mark)

The program code shows how the heart rate is entered.

Describe all the events that will occur if a user enters a negative value.

Answer explanation

Clear description must identify the following for all three marks:

• Implementation of conditional loop and the fact that condition is NOT met as number entered negative (one mark).

• Input value from keyboard (one mark).

• If statement with condition being met as data entered is negative, a negative error message is displayed and user asked to re-enter (one mark).

The program stops when the user enters 0.

The design is to be improved to display a warning message if the total is greater than 40.

Use pseudocode or a programming language of your choice

to show how this extra feature could be implemented:

Answer explanation

IF total > 40 THEN

SEND “Warning” TO DISPLAY

END IF

1 mark if statement

1 mark correct condition for if

1 mark for displaying warning message

A computer program is used to store a patient's heart rate each day for a week.

The seven readings are stored in an array of real numbers called "bpm".

Using pseudocode or a programming language of your choice,

write a short program to calculate the average heart rate of the patient

as stored in the array over the seven days.

Answer explanation

FOR days in range (7)

SET total TO total + bpm[days]

NEXT days

SET averagebpm TO total / 7

1 mark fixed loop for 7 days

1 mark running total using array

1 mark for calculation of average

Describe clearly, with reference to values and variables,

what the following pseudocode shown does.

Answer explanation

A description that covers the following points:

Values entered on form for “Create a password” and “Confirm your password” assigned to variables (one mark)

If statement used to compare these variables (one mark)

If the values match then a screen is shown confirming registration, otherwise an error message is displayed (one mark)

One mark for each bullet point.