This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Modelling the Diode Forward Characteristics”.

1. A voltage regulator needs to provide a constant voltage in spite of the fact that there may be

a) Change in the load current drawn from the terminals of the regulator

b) Change of the DC power supply that feeds the regulator circuit

c) None of the mentioned

d) All of the mentioned

(Q.3-Q.4) For the circuit shown below calculate

2. Calculate the %age change in the regulated voltage caused by a change of ±10% in the input voltage. (R_{L} is not connected to the circuit)

a) ± 0.5%

b) ± 1%

c) ± 5%

d) ± 10%

3. Which of the following is method to model a diode’s forward characteristics?

a) Iteration method

b) Graphical method

c) Constant-voltage drop model

d) All of the mentioned

4. Calculate the change in the voltage when R_{L} is connected as shown

a) -10 mA

b) -15 mA

c) -20 mA

d) -25 mA

5. In many applications, a conducting diode is modeled as having a constant voltage drop, usually approximately

a) 1 V

b) 0.1 V

c) 0.7 V

d) 7V

6. For small-signal operation around the dc bias point, the diode is modeled by a resistance equal to the

a) Slope of the i-v characteristics of the diode at the bias point

b) Square root of the slope of the i-v characteristics of the diode at the bias point

c) Inverse of the slope of the i-v characteristics of the diode at the bias point

d) Square root of the inverse of the slope of the i-v characteristics of the diode at the bias point

7. The value of the diode small-signal resistance r_{d} at bias currents of 0.1 mA is

a) 250 Ω

b) 25 Ω

c) 2.5 Ω

d) 0.25 Ω

8. The graphical method of modeling a diode characteristics is based on

a) Iteration method

b) Constant voltage drop method

c) Small signal approximation

d) Exponential method

9. The other name for bias point is

a) Quiescent point

b) Node point

c) Terminal point

d) Static point

10. In iteration method for modelling a diode the answer obtained by each subsequent iteration is

a) Is close to the true value

b) Is close to the value obtained by exponential method

c) All of the mentioned

d) None of the mentioned