DSY1501
ASSIGNMENT 1 2025
UNIQUE NO.
DUE DATE: 2025
, ASSESSMENT 1: INTRODUCTION TO DIGITAL CONCEPTS
Question 1 [12 Marks]
1.1
In a negative-logic pulse, the trailing edge is the:
✅ d) Falling edge
Explanation:
In digital electronics using negative logic, the signal is considered active when it's at a
low level. The trailing edge refers to when the signal returns from high to low, which is
known as the falling edge.
1.2
A square wave has an ‘on’ time of 10 ms and an ‘off’ time of 50 ms. What is the
percentage duty cycle?
✅ a) 16.66%
Calculation:
𝐃𝐮𝐭𝐲 𝐂𝐲𝐜𝐥𝐞 = (𝐓𝐨𝐧 + 𝐓𝐨𝐟𝐟𝐓𝐨𝐧) × 𝟏𝟎𝟎 = (𝟏𝟎 + 𝟓𝟎𝟏𝟎) × 𝟏𝟎𝟎 = (𝟔𝟎𝟏𝟎) × 𝟏𝟎𝟎 = 𝟏𝟔. 𝟔𝟔
1.3
What is the frequency of a pulse where Ton = 10 ms and Toff = 20 ms?
✅ c) 33.33 Hz
Calculation:
Ttotal = 10ms + 20ms = 30ms = 0.03s Frequency = 1T = 10.03
= 33.33 Hz\text{Frequency} = \frac{1}{T} = \frac{1}{0.03}
= 33.33\,\text{Hz}Frequency = T1 = 0.031 = 33.33Hz
ASSIGNMENT 1 2025
UNIQUE NO.
DUE DATE: 2025
, ASSESSMENT 1: INTRODUCTION TO DIGITAL CONCEPTS
Question 1 [12 Marks]
1.1
In a negative-logic pulse, the trailing edge is the:
✅ d) Falling edge
Explanation:
In digital electronics using negative logic, the signal is considered active when it's at a
low level. The trailing edge refers to when the signal returns from high to low, which is
known as the falling edge.
1.2
A square wave has an ‘on’ time of 10 ms and an ‘off’ time of 50 ms. What is the
percentage duty cycle?
✅ a) 16.66%
Calculation:
𝐃𝐮𝐭𝐲 𝐂𝐲𝐜𝐥𝐞 = (𝐓𝐨𝐧 + 𝐓𝐨𝐟𝐟𝐓𝐨𝐧) × 𝟏𝟎𝟎 = (𝟏𝟎 + 𝟓𝟎𝟏𝟎) × 𝟏𝟎𝟎 = (𝟔𝟎𝟏𝟎) × 𝟏𝟎𝟎 = 𝟏𝟔. 𝟔𝟔
1.3
What is the frequency of a pulse where Ton = 10 ms and Toff = 20 ms?
✅ c) 33.33 Hz
Calculation:
Ttotal = 10ms + 20ms = 30ms = 0.03s Frequency = 1T = 10.03
= 33.33 Hz\text{Frequency} = \frac{1}{T} = \frac{1}{0.03}
= 33.33\,\text{Hz}Frequency = T1 = 0.031 = 33.33Hz
