Refer to FIGURE 4.1 below and answer the questions that follow. 4.1.1 State whether the following are step-up or step-down transformers: (a) Transformer at (B) (b) Transformer at (C) 4.1.2 Name the expected voltage provided to the following consumers after transformer (D): (a) Household (b) Industrial 4.1.3 Explain why both household and industrial loads can be powered by transformer (D). 4.1.4 Explain why transformer (B) reduces copper losses in the transmission lines. 4.1.5 Draw a neatly labelled waveform generated at (A) in FIGURE 4.1 above.

NSC Electrical Technology Power Systems Power in Three-Phase Systems: Refer to FIGURE 4.1 below and an

Refer to FIGURE 4.1 below and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2023 - Paper 1

Question 4

Refer to FIGURE 4.1 below and answer the questions that follow. 4.1.1 State whether the following are step-up or step-down transformers: (a) Transformer at (B) (b) ... show full transcript

Worked Solution & Example Answer:Refer to FIGURE 4.1 below and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2023 - Paper 1

Step 1

4.1.1 State whether the following are step-up or step-down transformers:

96%

114 rated

Answer

(a) Transformer at (B): This is a step-up transformer that increases the voltage for better transmission over long distances.

(b) Transformer at (C): This is a step-down transformer that decreases the high voltage to a lower voltage suitable for industrial and household use.

Step 2

4.1.2 Name the expected voltage provided to the following consumers after transformer (D):

99%

104 rated

Answer

(a) Household: The expected voltage for household consumers is approximately 220 V.

(b) Industrial: The expected voltage for industrial consumers falls between 380 V and 415 V.

Step 3

4.1.3 Explain why both household and industrial loads can be powered by transformer (D).

96%

101 rated

Answer

Transformer (D) is connected in a star configuration, which allows it to create a neutral point. This enables the transformer to supply both single-phase and three-phase loads, accommodating different power needs effectively.

Step 4

4.1.4 Explain why transformer (B) reduces copper losses in the transmission lines.

98%

120 rated

Answer

Transformer (B) is a step-up transformer that increases the voltage in the transmission lines. According to the formula for power loss due to resistance, $P = I^2 R$ , increasing the voltage allows for a reduction in current. Since power loss is proportional to the square of the current, higher voltage means significantly lower losses.

Step 5

4.1.5 Draw a neatly labelled waveform generated at (A) in FIGURE 4.1 above.

97%

117 rated

Answer

Waveform

The waveform typically represents a sinusoidal AC signal, with key labels indicating the peak voltage, zero crossings, and phase angles.

Refer to FIGURE 4.1 below and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2023 - Paper 1

Worked Solution & Example Answer:Refer to FIGURE 4.1 below and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2023 - Paper 1

4.1.1 State whether the following are step-up or step-down transformers:

4.1.2 Name the expected voltage provided to the following consumers after transformer (D):

4.1.3 Explain why both household and industrial loads can be powered by transformer (D).

4.1.4 Explain why transformer (B) reduces copper losses in the transmission lines.

4.1.5 Draw a neatly labelled waveform generated at (A) in FIGURE 4.1 above.

Join the NSC students using SimpleStudy...