Question

please answer all questions

O The Hong Kong Polytechnic University Section A 1. (a) A digital thermometer is designed to measure temperature ranging from 20°C to 45°c. 0) Describe the two steps involved in the digitization of analog signals (4 marks) (i) If the quantization error is required to be less than O. I C, how many bits are required to encode the temperature readings? (4 marks) (ii)What is the temperature reading of 26.S°C in binary form after the digitization? Assume that the number of bits used to encode the temperature readings is the same as the answer found in (aXii). (4 marks) A digital storage device has a capacity of 2 GB and a writing speed of 10 MBps. Consider (b) full-color images with resolution of 2048x1536 pixels are to be copied to the storage device. 4 marks) (2 marks) What is the maximum number of images that can be stored in the storage device? (i) (ii) Calculate the time taken to copy 200 images to the storage device. Describe one main difference between system software and application software. (c) (2 marks) Page 2

Answer 1

A)

1. Digitization is the process of converting information into digital format. Information is converted into binary format which computer can process. It has two different steps: Sampling and quantization

Sampling: Here the data is sampled at regular intervals. It converts analog data into discrete data.here data occurs in distinct units.

Quantization: Here the numerical values from fixed range are assigned.

B)

1: Storage device capacity is 2 GB = 2000000 KB

Image resolution is 2048 *1536 So approximate size of image will be 756 kb

Therefore total number of images that can be stored in device = 2000000/756 =2645.50

Therefore 2645 images can be stored in storage device.

C) Main difference between system software and application software:

System software is used for operating computer hardware and Application software is used for performing user specific task.

Example of system software: Compiler, Driver

Application software : Word processor, media player