Input and output devices Computer Science 0478

Input devices allow ________, instructions, or signals to be entered into a computer system for processing.

• data

• output

• storage

• display

Answer explanation

Input devices allow data to be entered into a computer system for processing. The term 'data' refers to the information or signals that are inputted, making it the correct choice over output, storage, or display.

Match the following categories of input devices to their examples:

• Barcode reader, OCR, MICR, OMR

• Touch-based

• Temperature, light, motion

• Audio/visual input

• Microphone, digital camera, scanner

• Direct data entry

• Touchscreen, touchpad

• Manual input

• Keyboard, mouse, joystick

• Sensors

Which of the following is an example of a touch-based input device?

• Keyboard

• Barcode reader

• Touchscreen

• Microphone

Answer explanation

A touchscreen is a touch-based input device that allows users to interact directly with what is displayed, unlike a keyboard, barcode reader, or microphone, which use different input methods.

A microphone is an example of an audio/visual input device.

• True

• False

Answer explanation

A microphone captures sound, making it an audio input device. It does not provide visual input, but it is still classified as an audio/visual input device in broader contexts, hence the answer is True.

Touchscreens act as both ________ and ________ devices.

• input, output

• output, input

• storage, output

• input, storage

Answer explanation

Touchscreens serve as both input and output devices. They allow users to input commands through touch while also displaying information visually, making 'input, output' the correct choice.

Which category does a barcode reader belong to?

• Manual input

• Direct data entry

• Sensors

• Touch-based

Answer explanation

A barcode reader is a device that captures data directly from barcodes, making it a form of direct data entry. It automatically inputs information into a system without manual typing, distinguishing it from manual input methods.

How does a resistive touchscreen work?

• It uses a glass coated with a conductive layer that stores electrical charge.

• It is made of two layers: one conductive and one resistive, separated by a thin air gap. When pressure is applied, the two layers make contact and the location of the touch is detected by measuring the change in electrical current.

• It uses sensors at the screen’s corners to detect the drop in charge.

• It only works with fingers or capacitive stylus.

Answer explanation

A resistive touchscreen consists of two layers: one conductive and one resistive, with a thin air gap. When pressure is applied, these layers touch, allowing the device to detect the touch location by measuring changes in electrical current.

Which of the following is an advantage of resistive touchscreens?

• Excellent visibility in sunlight

• Works with stylus, gloves, or any object

• Multi-touch support

• Very responsive

Answer explanation

Resistive touchscreens are unique in that they can be operated with a stylus, gloves, or any object, making them versatile for various environments. This is a key advantage over other touchscreen types.

Fill in the blank: One disadvantage of resistive touchscreens is that they require ______, making them less sensitive.

• pressure

• light

• sound

• heat

Answer explanation

One disadvantage of resistive touchscreens is that they require pressure to register input. This reliance on pressure makes them less sensitive compared to other types of touchscreens that can detect lighter touches.

How does a capacitive touchscreen work?

• It is made of two layers: one conductive and one resistive, separated by a thin air gap.

• It is made of glass coated with a conductive layer that stores electrical charge. When a finger touches the screen, a small amount of charge transfers to the user, and sensors at the screen’s corners detect the drop in charge to determine position.

• It works with stylus, gloves, or any object.

• It can be easily scratched.

Answer explanation

A capacitive touchscreen consists of a glass layer with a conductive coating. When a finger touches it, some charge transfers, and sensors detect the change to pinpoint the touch location.