Complete the following sentences by filling in the missing word(s). Write only the missing words next to the question number.
1.2.1 If it takes exactly 0,02... for the waveform of a single-phase alternating supply to complete one full cycle, the frequency of that supply is... Hertz.
1.2.2 In the physical layout of the drawing, the draughtsman may... any graphical symbol in the electrical diagram on condition that the meaning or... will not be altered thereby.
1.2.3 IEC publication number (113/617/750/0142) deals with Graphical Symbols for Diagrams.
1.2.4 SANS 10142, Code of Practice for the...
Answer (2)
Calculate the frequency: f re q u e n cy = 0.02 1 = 50 Hertz.
The draughtsman may alter any graphical symbol, provided that the meaning is not changed.
The IEC publication number that deals with graphical symbols for diagrams is 617.
SANS 10142 is the Code of Practice for the Wiring of Premises .
The final answers are: 1.2.1: 50 1.2.2: a lt er , m e anin g 1.2.3: 617 1.2.4: Wi r in g o f P re mi ses
Explanation
Analyzing the Sentences We need to complete the sentences with the correct missing words. Let's analyze each sentence individually.
Calculating the Frequency 1.2.1: The sentence discusses the relationship between the time it takes for a waveform to complete a cycle and the frequency of the supply. We know that frequency is the inverse of the time period. Given the time period is 0.02 seconds, we can calculate the frequency.
Frequency Calculation The frequency is calculated as: f re q u e n cy = t im e 1 = 0.02 1 = 50 Hertz.
Draughtsman's Actions 1.2.2: This sentence refers to the draughtsman's ability to modify graphical symbols in an electrical diagram. The draughtsman may alter any graphical symbol, provided that the meaning is not changed.
IEC Publication Number 1.2.3: This sentence asks for the IEC publication number that deals with graphical symbols for diagrams. The correct number is 617.
SANS 10142 Description 1.2.4: This sentence asks what SANS 10142 is a code of practice for. SANS 10142 is the Code of Practice for the Wiring of Premises .
Final Answer Therefore, the missing words are: 1.2.1: 50 1.2.2: alter, meaning 1.2.3: 617 1.2.4: Wiring of Premises
Examples
Understanding frequency is crucial in many real-world applications. For example, in music, the frequency of a sound wave determines the pitch we hear. In electrical engineering, knowing the frequency of an AC power supply is essential for designing and operating electrical equipment safely and efficiently. Similarly, graphical symbols are used universally to represent electrical components in circuit diagrams, ensuring clear communication among engineers and technicians. Standards like SANS 10142 ensure electrical installations are safe and compliant with regulations, protecting people and property from electrical hazards.
The answers are: 1.2.1: 50 Hertz, 1.2.2: alter, meaning, 1.2.3: 617, and 1.2.4: Wiring of Premises.
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