Refer to FIGURE 2.1 below and answer the questions that follow - NSC Electrical Technology Digital - Question 2 - 2021 - Paper 1
Question 2
Refer to FIGURE 2.1 below and answer the questions that follow.
2.1.1 Identify the multivibrator in FIGURE 2.1.
2.1.2 State the polarity of the pulse provided on t... show full transcript
Worked Solution & Example Answer:Refer to FIGURE 2.1 below and answer the questions that follow - NSC Electrical Technology Digital - Question 2 - 2021 - Paper 1
Step 1
Identify the multivibrator in FIGURE 2.1.
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Answer
The multivibrator in FIGURE 2.1 is an astable multivibrator since it continuously oscillates between high and low output states without requiring an external trigger.
Step 2
State the polarity of the pulse provided on the inverting input when switch S1 is pressed.
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Answer
When switch S1 is pressed, the pulse provided on the inverting input is negative, as it is connected to ground which serves as a reference point.
Step 3
State TWO functions of the 741 op-amp in the circuit.
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Answer
The 741 op-amp acts as a comparator, comparing the voltage levels at the inverting and non-inverting inputs to determine the output state.
It also amplifies the voltage difference between the two inputs to drive the output high or low.
Step 4
In which LEVEL will the output be raised when S1 is pressed.
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The output will be raised to a high level (near +9V) when S1 is pressed, signaling a transition from low to high state.
Step 5
State the polarity of the voltage present on pin 3 after switch S1 is pressed.
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Answer
After switch S1 is pressed, the polarity of the voltage present on pin 3 is positive, indicating that the op-amp is in the active high state.
