WAEC SSCE - Computer Studies - 2021 (Essay)

(a)(i) Define computer graphics.

Computer graphics is the branch of computing concerned with creating, storing, editing and displaying pictures, images, drawings and other visual content using a computer. It covers both the pictures produced (such as diagrams, charts and animations) and the techniques and software used to generate and manipulate them.

(a)(ii) Two applications of computer graphics in advertising:

• Designing posters, banners, flyers and billboards for products.
• Producing logos, product packaging designs and animated television or online adverts.

(b) One use of each graphics tool:

• (i) Interactive Fill Tool: used to apply and adjust a fill (colour, gradient or pattern) inside an object interactively by dragging directly on the object.
• (ii) Texture Fill Tool: used to fill an object with a textured, natural-looking pattern (such as clouds, water, marble or rock) instead of a plain colour.
• (iii) Envelope Tool: used to reshape or distort an object or text by dragging its surrounding frame (envelope) so the object bends to a new shape.
• (iv) Extrude Tool: used to give a flat object a three-dimensional (3D) appearance by adding depth/perspective to it.

(c) Name one Fill Tool needed to:

• (i) create a background faded from light blue to white: the Fountain Fill (Gradient) Tool.
• (ii) fill an object with two colours that blend from one to another: the Fountain Fill (Gradient) Tool (a two-colour linear/radial gradient).

QBASIC program to grade a score as "Poor" or "Satisfactory"

The program keeps asking for a score. If the score entered is less than zero, it stops immediately. Otherwise it prints "Poor" for a score below 50 and "Satisfactory" for a score of 50 or above.

REM Program to grade scores
CLS
DO
    INPUT "Enter a score (negative to stop): ", SCORE
    IF SCORE < 0 THEN
        EXIT DO
    END IF
    IF SCORE < 50 THEN
        PRINT "Poor"
    ELSE
        PRINT "Satisfactory"
    END IF
LOOP
END

How it works:

• The DO ... LOOP repeats so that many scores can be graded one after another.
• INPUT reads a score from the keyboard.
• If SCORE < 0, the EXIT DO statement ends the loop and the program stops.
• The IF ... ELSE statement tests the score: below 50 prints Poor; equal to or above 50 prints Satisfactory (since 50% is the boundary and belongs to Satisfactory).

Alternative using GOTO (also acceptable):

CLS
Start:
INPUT "Enter a score: ", SCORE
IF SCORE < 0 THEN END
IF SCORE < 50 THEN PRINT "Poor" ELSE PRINT "Satisfactory"
GOTO Start

(a)(i) Universal Serial Bus (USB):

Universal Serial Bus (USB) is a standard plug-and-play interface used to connect a computer to peripheral devices such as keyboards, mice, printers, scanners, flash drives, cameras and mobile phones for communication, data transfer and power supply.

(a)(ii) Benefits of USB connection:

• It supports plug-and-play; connected devices are automatically detected and configured.
• It allows data transfer and can also supply low-voltage power to devices through the same cable.

(b) Identification and category of storage devices:

Universal Serial Bus (USB) is a standard plug-and-play interface used to connect a computer to peripheral devices such as keyboards, mice, printers, scanners, flash drives, cameras and mobile phones for communication, data transfer and power supply.

(a)(ii) Benefits of USB connection:

• It supports plug-and-play; connected devices are automatically detected and configured.
• It allows data transfer and can also supply low-voltage power to devices through the same cable.

(b) Identification and category of storage devices:

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