Evaluating USB for a given use

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. A student wants to connect a printer to a laptop on the same desk. Is USB a suitable choice?

A Yes - USB is universal and plug and play, and the short cable is not a problem on one desk

B No - USB cannot connect printers because it only works with keyboards

2. A school needs to connect a printer in a room 30 metres away from a computer. Which evaluation is best?

A USB is ideal because USB cables can be any length without losing signal

B USB may be unsuitable because its cable length is limited, so another method may be needed

3. Which statement is a valid justification for using USB to connect an external drive?

A It is the only connection that can ever transfer data between two devices

B It is plug and play, so the computer detects the drive and sets it up automatically

4. When evaluating USB for a scenario, what should you do?

A Weigh its benefits and drawbacks against what the scenario needs

B List only the benefits because USB is always the best choice

5. Which is a drawback of USB that matters when the devices are far apart?

A Limited cable length

B The connector only fits one way round on every device

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Evaluate USB: printer, 1 m away		AIt ignores the drawbacks and the scenario. An evaluation must weigh benefits against drawbacks for the specific use.
2Evaluate USB: sensor, 50 m away		BUSB suits this use because plug and play and a universal connector make setup easy, and a short cable is enough
3A good evaluation links a USB benefit to the scenario's needs, such as an external drive needing easy setup		CUSB has a short cable length, but this does not matter as the printer sits on the same desk.
4A balanced evaluation also states a drawback and says whether it matters for the scenario		DUSB is a poor choice because the cable length is too short and signals weaken over distance
5USB is always the best choice because it has benefits.		EUSB suits an external drive because it is plug and play, so the computer detects it automatically.
6USB is bad for a printer because the cable is short.		FIt only states a drawback and ignores the scenario. A printer is usually close to the computer, so cable length is not a problem.

Definitions

Evaluate USB

Fill in the Blanks

Complete each line of code by filling in the missing parts.

IF cableNeeded _ maxCable THEN OUTPUT "USB not suitable" ENDIF

IF device = "printer" THEN ______ "USB suits: plug and play" ENDIF

IF cableNeeded > 5 THEN OUTPUT "Cable too long for USB" _____

needsPlugAndPlay ← TRUE IF ________________ = TRUE THEN OUTPUT "USB is a good fit"

IF isPrinter ___ cableNeeded <= 3 THEN OUTPUT "USB suits this use" ENDIF

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A scenario ← printer on desk

B cableNeeded ← 2

C IF cableNeeded <= 5 THEN

D OUTPUT "USB suits this"

E ENDIF

Question 2

A distance ← 20

B IF distance > 5 THEN

C OUTPUT "Cable too long"

D OUTPUT "USB is a good fit"

E ENDIF

Question 3

A device ← "printer"

B usbIsUniversal ← TRUE

C IF usbIsUniversal

D OUTPUT "Works on many PCs"

E ENDIF

Question 4

A length ← 8

B maxLen ← 5

C IF length < maxLen THEN

D OUTPUT "Too long for USB"

E ENDIF

Question 5

A device ← "USB printer"

B OUTPUT "Setup by hand needed"

C OUTPUT "USB is a good fit"

Answer Key

Evaluating USB for a given use

Section A: Quick Questions

A — Yes - USB is universal and plug and play, and the short cable is not a problem on one desk

B — USB may be unsuitable because its cable length is limited, so another method may be needed

B — It is plug and play, so the computer detects the drive and sets it up automatically

A — Weigh its benefits and drawbacks against what the scenario needs

A — Limited cable length

Section B: Match the Pairs

Evaluate USB: printer, 1 m away → USB suits this use because plug and play and a universal connector make setup easy, and a short cable is enough

Evaluate USB: sensor, 50 m away → USB is a poor choice because the cable length is too short and signals weaken over distance

A good evaluation links a USB benefit to the scenario's needs, such as an external drive needing easy setup → USB suits an external drive because it is plug and play, so the computer detects it automatically.

A balanced evaluation also states a drawback and says whether it matters for the scenario → USB has a short cable length, but this does not matter as the printer sits on the same desk.

USB is always the best choice because it has benefits. → It ignores the drawbacks and the scenario. An evaluation must weigh benefits against drawbacks for the specific use.

USB is bad for a printer because the cable is short. → It only states a drawback and ignores the scenario. A printer is usually close to the computer, so cable length is not a problem.

Section C: Definitions

Evaluate USB — Judge if USB suits a use by weighing benefits (universal, plug and play) against drawbacks (short cable length, limited speed) for the scenario, such as a printer or drive.

Section D: Fill in the Blanks

IF cableNeeded > maxCable THEN
  OUTPUT "USB not suitable"
ENDIF

IF device = "printer" THEN
  OUTPUT "USB suits: plug and play"
ENDIF

IF cableNeeded > 5 THEN
  OUTPUT "Cable too long for USB"
ENDIF

needsPlugAndPlay ← TRUE
IF needsPlugAndPlay = TRUE THEN
  OUTPUT "USB is a good fit"

IF isPrinter AND cableNeeded <= 3 THEN
  OUTPUT "USB suits this use"
ENDIF

Section E: Spot the Error

A — The text value is missing its quotes. A string must be written in quotes: scenario ← "printer on desk".

D — The cable needed (20) is longer than USB allows, so USB is a poor fit. Saying it is a good fit contradicts the line above it.

C — The IF statement is missing THEN. It should be: IF usbIsUniversal THEN.

C — The wrong comparison operator is used. The message says the cable is too long, so the test must be length > maxLen.

B — USB is plug and play, so the computer detects the device automatically. It should not need manual setup, which is a benefit of USB.