Analog Circuits

Load Line Analysis

Question 1
Marks : +2 | -2
Pass Ratio : 11%
What is the change in voltage across the resistor when the load line is shifted from R1 to R2?
0 V
9.25 V
10 V
9 V
Explanation:
The value of voltage calculated across the resistor is calculated by E-VD, which is constant for both cases.
Question 2
Marks : +2 | -2
Pass Ratio : 22%
From the given load characteristics, what is the value of diode current at operating point for the characteristics of R2?
9.3 mA
4.6 mA
0 mA
10 mA
Explanation:
At the point of intersection, the value of current is around 4.6 mA.
Question 3
Marks : +2 | -2
Pass Ratio : 39%
From the circuit and the diode characteristics given and assuming R=1k, what is the value of voltage across the resistor at operating point?
10 V
0 V
9.3 V
10.7 V
Explanation:
We know that VR=IDR = 9.3 x 1 = 9.3 V.
Question 4
Marks : +2 | -2
Pass Ratio : 33%
From the given load characteristics, what is the value of diode voltage at operating point for the characteristics of R2?
0 V
10 V
0.7 V
1 V
Explanation:
At the point of intersection, the value of diode voltage is approximately 0.7 V.
Question 5
Marks : +2 | -2
Pass Ratio : 22%
Using the ideal diode model of a silicon diode and taking E=10 V and R=1k, what is the value of diode voltage at operating point?
0.7 V
0 V
10 V
0.3V
Explanation:
In ideal diode model, we take the forward threshold voltage to be zero. Hence the diode characteristic is represented as the upper half of the y-axis. Hence, VD = 0 V.
Question 6
Marks : +2 | -2
Pass Ratio : 33%
From the circuit and the diode characteristics given and assuming R=1k, what is the value of diode current at operating point?
20 mA
9.3 mA
0 mA
10 mA
Explanation:
On drawing the load line with the equation: VD = ED + IDRD, we get the operating point with the value of current at around 9.2-9.4 mA. Hence, IDq=9.3 mA.
Question 7
Marks : +2 | -2
Pass Ratio : 11%
From the circuit and the diode characteristics given alongside, and assuming R=2k, what is the value of diode voltage at the operating point?
0.78 V
10 V
0 V
1v
Explanation:
On drawing the load line with the equation: VD = ED + IDRD, we get the operating point with the value of at voltage at around 0.7-0.8 V. Hence, VDq=0.78 V.
Question 8
Marks : +2 | -2
Pass Ratio : 11%
Using the approximate equivalent model of a silicon diode and taking E=10 V and R=1k, what is the value of diode current at operating point?
9.25 mA
10 mA
0 mA
9.5 mA
Explanation:
In the approximate equivalent model, the characteristic is assumed to be a vertical upward line at V=0.7 V. Hence, the current at point of intersection is determined to be 9.25 mA
Question 9
Marks : +2 | -2
Pass Ratio : 39%
From the given load line characteristics, what is the relation between R1 and R2 , assuming constant source EMF?
R1 > R2
R1 = R2
R1 < R2
R1 >= R2
Explanation:
Here, the y-intercept=E/R hence, lower the y-intercept, higher the value of R, Hence, R1<R2
Question 10
Marks : +2 | -2
Pass Ratio : 22%
Using the approximate equivalent model of a silicon diode and taking E=10 V and R=1k, what is the value of diode voltage at operating point?
0.7 V
0.3 V
10 V
9.3 V
Explanation:
In the approximate equivalent model, the diode voltage is fixed at the forward bias threshold voltage, which for a silicon diode is equal to 0.7 V