Electronic Devices and Circuits – Multiple Choice Questions (MCQs)

1. 37. Photodiodes are used in the ________ bias mode.

   • A. Forward
   • B. Reverse
   • C. Zero
   • D. Breakdown

2. 38. The characteristic curve of a tunnel diode exhibits a ________ resistance region.

   • A. Positive
   • B. Negative
   • C. Zero
   • D. Infinite

3. 39. What is the main advantage of a Schottky diode over a P-N junction diode?

   • A. Lower forward voltage drop
   • B. Higher reverse breakdown voltage
   • C. Faster switching speed
   • D. Both A and C

4. 40. A varactor diode is primarily used as a voltage-controlled:

   • A. Resistor
   • B. Inductor
   • C. Capacitor
   • D. Diode

5. 41. The minority carriers in an N-type semiconductor are:

   • A. Electrons
   • B. Holes
   • C. Ions
   • D. Protons

6. 42. The built-in potential barrier of a P-N junction is due to:

   • A. Doping
   • B. Diffusion of charge carriers
   • C. Recombination of charge carriers
   • D. External voltage

7. 43. What is the typical output impedance of an ideal Op-Amp?

   • A. Zero
   • B. Infinite
   • C. Low
   • D. High

8. 44. An integrator circuit using an Op-Amp will have its output proportional to the ________ of the input signal.

   • A. Derivative
   • B. Integral
   • C. Sum
   • D. Difference

9. 45. A differentiator circuit using an Op-Amp will have its output proportional to the ________ of the input signal.

   • A. Derivative
   • B. Integral
   • C. Sum
   • D. Difference

10. 46. The slew rate of an Op-Amp is a measure of its:

    • A. Voltage gain
    • B. Speed of response
    • C. Input impedance
    • D. Output impedance

11. 47. The gain-bandwidth product of an Op-Amp is:

    • A. Constant
    • B. Dependent on frequency
    • C. Dependent on gain
    • D. Infinite

12. 48. What is the primary function of a heat sink used with power transistors?

    • A. To reduce resistance
    • B. To dissipate heat
    • C. To increase current
    • D. To improve voltage gain