3.1 Name the type of material used for the gate terminal in a P-channel JFET - NSC Electrical Technology Electronics - Question 3 - 2019 - Paper 1
Question 3
3.1 Name the type of material used for the gate terminal in a P-channel JFET.
3.2 Draw a neatly labelled symbol of an N-channel JFET.
3.3 Study the symbol in FIGUR... show full transcript
Worked Solution & Example Answer:3.1 Name the type of material used for the gate terminal in a P-channel JFET - NSC Electrical Technology Electronics - Question 3 - 2019 - Paper 1
Step 1
3.1 Name the type of material used for the gate terminal in a P-channel JFET.
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Answer
The type of material used for the gate terminal in a P-channel JFET is N-type semiconductor.
Step 2
3.2 Draw a neatly labelled symbol of an N-channel JFET.
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Answer
The symbol for an N-channel JFET consists of a vertical line representing the channel, with three terminals: Drain (D), Gate (G), and Source (S). Label each terminal accordingly.
Step 3
3.3.1 State whether the field-effect transistor (FET) in FIGURE 3.3 is a P-channel or an N-channel.
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Answer
The field-effect transistor (FET) in FIGURE 3.3 is an N-channel.
Step 4
3.3.2 List THREE conditions for the correct biasing of the transistor in FIGURE 3.3.
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The Drain must be connected to the positive voltage.
The Source must be connected to the negative voltage.
The Gate voltage must be positive.
Step 5
3.4.1 Besides a sawtooth generator, name ONE other application of a UJT.
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Answer
One other application of a UJT is in oscillators.
Step 6
3.4.2 Explain what causes the UJT to trigger ON in the circuit.
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The UJT triggers when the voltage across the capacitor/emitter rises to 0.7V above the intrinsic standoff ratio (Vx or Vbb). Furthermore, it also triggers when the voltage reaches the UJT's peak voltage (Vp).
Step 7
3.4.3 Draw the output waveform between points B1 and ground on the ANSWER SHEET for QUESTION 3.4.3.
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Answer
The output waveform would depict a sawtooth pattern, illustrating the charging and discharging phases of the capacitor across B1 and ground.
Step 8
3.5.1 State how you would identify pin 1 of the IC in FIGURE 3.5.
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Pin 1 is identified by being the first pin to the left and below the indentation, or it can also be identified as being closest to the dot in the body of the IC.
Step 9
3.5.2 List the THREE stages into which the internal circuit of the op-amp is divided.
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Input stage or differential amplifier.
Intermediate stage or high gain differential amplifier.
Output stage or common collector.
Step 10
3.6.1 Calculate the output voltage based on the data in FIGURE 3.6.
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The output voltage (VOUT) is calculated using the formula: VOUT=VIN(RNRF)
Substituting the values: =2×(12k100k)=−16.67V
Step 11
3.6.2 Explain why the shape of the output waveform is NOT an exact replica of the input waveform.
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Answer
The amplifier is driven into saturation, causing the tops and bottoms to be clipped. Additionally, since the input is fed into the inverting input, there is a 180-degree phase shift on the output.
Step 12
3.6.3 Identify the maximum output voltages (VOUT).
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The maximum output voltages (VOUT) are +15 volts and -15 volts.
Step 13
3.7.1 Rewrite the abbreviation DIP in full.
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DIP stands for Dual in-line package.
Step 14
3.7.2 Write down the maximum supply voltage for the NE555 IC.
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Answer
The maximum supply voltage for the NE555 IC is +15 volts.
Step 15
3.7.3 Identify the typical trigger voltage of the NE555 IC, in the data sheet above, when the supply voltage is +15 V.
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Answer
The typical trigger voltage of the NE555 IC is 1/3 of the supply voltage, which would be approximately 5V when the supply voltage is +15V.
Step 16
3.8 Explain what will happen to the output of an NE555 IC when the trigger voltage rises above the threshold voltage level of 10 V.
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When the trigger voltage rises above the threshold voltage level of 10V, the output of the NE555 IC will switch to a high state, activating the output pin.
