Refer to FIGURE 5.1 below and answer the questions that follow - NSC Electrical Technology Electronics - Question 5 - 2021 - Paper 1
Question 5
Refer to FIGURE 5.1 below and answer the questions that follow.
5.1.1 State the function of resistor R1.
5.1.2 Write down the voltage across Pin 2 when switch S is... show full transcript
Worked Solution & Example Answer:Refer to FIGURE 5.1 below and answer the questions that follow - NSC Electrical Technology Electronics - Question 5 - 2021 - Paper 1
Step 1
5.1.1 State the function of resistor R1.
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Answer
Resistor R1 acts as a pull-up resistor, keeping pin 2 high and maintaining the stability of the circuit when no input is present.
Step 2
5.1.2 Write down the voltage across Pin 2 when switch S is pressed.
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The voltage across Pin 2 is 0 V when switch S is pressed, as the path to ground is completed.
Step 3
5.1.3 State whether the LED will be ON or OFF when switch S is pressed.
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The LED will be ON when switch S is pressed, as it receives the necessary voltage to illuminate.
Step 4
5.1.4 Determine the typical threshold voltage of the circuit.
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The typical threshold voltage of the circuit is approximately rac{2}{3} V_{cc}, which is around 6 V if Vcc=9V.
Step 5
5.1.5 Explain why the switch bounce does not affect the output of the circuit.
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The switch bounce duration is shorter than the charging cycle of the capacitor, preventing any significant disturbance in the output. Only when the capacitor charges sufficiently does the circuit change state.
Step 6
5.1.6 Draw the output on the ANSWER SHEET for QUESTION 5.1.6.
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The output will show a series of pulses correlating to the switch bounces until the capacitor fully charges, resulting in a stable output.
