7.1 Name TWO characteristics of an ideal op amp - English General - NSC Electrical Technology Electronics - Question 7 - 2016 - Paper 1
Question 7
7.1 Name TWO characteristics of an ideal op amp.
7.2 Describe the term bandwidth.
7.3 Describe the term positive feedback.
7.4 Draw and label the circuit symbol o... show full transcript
Worked Solution & Example Answer:7.1 Name TWO characteristics of an ideal op amp - English General - NSC Electrical Technology Electronics - Question 7 - 2016 - Paper 1
Step 1
Name TWO characteristics of an ideal op amp.
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Answer
The open-loop voltage gain (
A_v) is infinite.
The input impedance (Z_in) is infinite.
Step 2
Describe the term bandwidth.
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Answer
The bandwidth is the range of frequencies within which an amplifier can operate without causing distortion to the output signal. It defines the frequencies over which the amplifier acts linearly or maintains its specified gain.
Step 3
Describe the term positive feedback.
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Positive feedback occurs when the output signal of an amplifier is fed back into the input in phase with the original input signal. This can lead to an increase in output and can potentially drive the system towards saturation.
Step 4
Draw and label the circuit symbol of an op amp. Include the power terminals.
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Answer
The circuit symbol for an op-amp consists of a triangle shape pointing to the right. The non-inverting input (+) is at the top, the inverting input (-) at the bottom, and the output at the apex of the triangle. The power terminals are indicated as +V_supply and -V_supply.
Step 5
With reference to the ideal op-amp circuits below, draw the given input and output wave-form diagrams on the same y-axis. Label the wave forms.
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Answer
The input wave form is a sinusoidal waveform represented as V1 and the output wave form is the inverted version of V1 represented as Vout. These should be plotted on the same y-axis for clarity.
Step 6
Identify the op-amp configuration.
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Answer
The op-amp configuration is a non-inverting amplifier.
Step 7
Draw the input and output signal on the same y-axis. Label the wave forms.
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Answer
The input wave form should be a sine wave, and the output should be a sine wave that is both amplified and in the same phase.
Step 8
Calculate the voltage gain.
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Answer
The voltage gain (A_v) can be calculated using the formula:
A_v = rac{V_{out}}{V_{in}} = 1 + rac{R_f}{R_{in}}
In this case, the gain equals 4.
Step 9
Calculate the output voltage if an input signal of 2.5 V is applied to the op amp.
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Using the found voltage gain, the output voltage can be calculated as follows:
Vout=AvimesVin=4imes2.5extV=10extV
Step 10
Name TWO applications of an astable multivibrator circuit.
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Answer
Tone generator
Square wave generator
Step 11
With reference to FIGURE 7.4, draw the input wave form shown in FIGURE 7.5 and the output wave form directly below it.
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The input wave form is a square wave signal with specific voltage levels denoted and the output wave form will reflect the behavior of the astable multivibrator based on the input.
Step 12
Identify the type of feedback used in the RC phase-shift oscillator.
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The type of feedback used is positive feedback.
Step 13
State ONE application of the oscillator.
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One application of the oscillator is as a tone generator.
Step 14
Calculate the oscillation frequency for an RC phase-shift oscillator that uses three RC networks. The resistors are all 15 Ω.
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The oscillation frequency can be calculated using the following formula:
f_{osc} = rac{2 riangle}{6R_{total}C}
Substituting the values gives an oscillation frequency of approximately 43.31 Hz.
Step 15
State ONE application of the integrator circuit.
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One application of an integrator circuit is in signal processing, specifically in analog signal integration.
Step 16
Draw the input and output wave forms of the op-amp integrator circuit.
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The input wave form is typically a square wave, while the output wave form will generally be a triangular wave, dependent on the operational frequency and characteristics of the circuit.
