MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Thevenin theorem replaces a complicated circuit facing a load by an |
| A. | Ideal voltage source and parallel resistor |
| B. | Ideal current source and parallel resistor |
| C. | Ideal voltage source and series resistor |
| D. | Ideal current source and series resistor |
| Answer» D. Ideal current source and series resistor | |
| 2. |
Suppose the peak value of a sinusoidal voltage is 50 V. What is the rms value? |
| A. | 37.4 V |
| B. | 35.4 V |
| C. | 38.74 V |
| D. | 30.4 V |
| Answer» C. 38.74 V | |
| 3. |
A step-up transformer has a turns ratio of 1:4. If the line voltage is 115 V rms, what is the peak secondary voltage? |
| A. | 700 V |
| B. | 707 V |
| C. | 651 V |
| D. | 208 V |
| Answer» D. 208 V | |
| 4. |
Voltage is |
| A. | The flow of charged particles through a material |
| B. | The smallest electrically charged particle |
| C. | Trie force that causes electrons to flow |
| D. | The number of free electrons in an atom |
| Answer» D. The number of free electrons in an atom | |
| 5. |
A power transformer steps 100 V down to 10 V. If the current in its primary winding is 2 A, what is the current in the secondary winding? |
| A. | 50 A |
| B. | 0 |
| C. | 0.20833333333333 |
| D. | 20 A |
| Answer» E. | |
| 6. |
When operating above its resonant frequency, a series RLC circuit has the characteristics of a: |
| A. | series RL circuit |
| B. | series RC circuit |
| C. | series RLC circuit operated below its resonant frequency |
| D. | purely resistive circuit |
| Answer» B. series RC circuit | |
| 7. |
What causes the depletion layer? |
| A. | Doping |
| B. | Recombination |
| C. | Barrier potential |
| D. | Ions |
| Answer» D. Ions | |
| 8. |
Which one of the following statements is true for the voltage in a parallel RC circuit? |
| A. | The voltage always has the same amplitude and phase for every part of the circuit |
| B. | The total voltage is equal to the sum of the voltages across the resistance and capacitance |
| C. | The total voltage leads the total current by less than 90 degree |
| D. | The total voltage is less than the sum of the voltages across the resistance and capacitance |
| Answer» B. The total voltage is equal to the sum of the voltages across the resistance and capacitance | |
| 9. |
Which one of the following properties of a magnetic circuit can be directly compared to voltage in an electrical circuit? |
| A. | Flux density |
| B. | Number of lines of force |
| C. | Magnetomotive force |
| D. | Reluctance |
| Answer» D. Reluctance | |
| 10. |
An unloaded zener regulator has a source voltage of 20 V, a series resistance of 330 W, and a zener voltage of 12 V, What is the Zener current? |
| A. | 28.4 mA |
| B. | 24.2 mA |
| C. | 34.4 mA |
| D. | 68.4 mA |
| Answer» C. 34.4 mA | |
| 11. |
What is the inductive reactance of a 2-H coil operating at 60 Hz? |
| A. | 754 Ohm |
| B. | 30 Ohm |
| C. | 60 Ohm |
| D. | 120 Ohm |
| Answer» B. 30 Ohm | |
| 12. |
What kind of device is a diode? |
| A. | Bilateral |
| B. | Linear |
| C. | Nonlinear |
| D. | Unipolar |
| Answer» D. Unipolar | |
| 13. |
The period of a waveform is: |
| A. | the time required to complete one full cycle |
| B. | the number of cycles completed in one second |
| C. | the time required for the voltage to rise from 10% to 90% of the peak amplitude |
| D. | equal to 0.707 times the peak amplitude |
| Answer» B. the number of cycles completed in one second | |
| 14. |
Current can flow through a normally open push button switch as long as: |
| A. | you are pressing the button |
| B. | you are not pressing the button |
| C. | its contact remain open |
| D. | its contact remain open |
| Answer» C. its contact remain open | |
| 15. |
Suppose a current source has an Ideal current of 10 mA and an internal resistance of 20 MW. For what values of load resistance will the current source appear stiff? |
| A. | 20 k Ohm or more |
| B. | 200 k Ohm or less |
| C. | 200 k Ohm or more |
| D. | 20 km or less |
| Answer» C. 200 k Ohm or more | |
| 16. |
Which one of the following statements most accurately describes the nature of inductive reactance? |
| A. | Inductive reactance is an opposition to current flow in dc circuits |
| B. | Inductive reactance is an opposition to current flow in ac circuits |
| C. | Inductive reactance is another term for counter emf |
| D. | Inductive reactance is a force that tends to overcome the effects of counter emf |
| Answer» C. Inductive reactance is another term for counter emf | |
| 17. |
For normal operation of the transistor, the collector diode has to be |
| A. | Forward-biased |
| B. | Reverse-biased |
| C. | Nonconducting |
| D. | Operating in the breakdown region |
| Answer» C. Nonconducting | |
| 18. |
The current gain of a transistor is defined as the ratio of the collector current to the |
| A. | base current |
| B. | emitter current |
| C. | supply current |
| D. | collector current |
| Answer» B. emitter current | |
| 19. |
How much current flows through a 0.02 micro F capacitor that is operating from a 12-V ac, 100-Hz source? |
| A. | 0.151 mA |
| B. | 157 raA |
| C. | 0.995 mA |
| D. | 2.02 A |
| Answer» B. 157 raA | |
| 20. |
What is the phase shift between total current and voltage, if 100 ohm resistor connected in parallel with an inductor that has a reactance of 200W? |
| A. | 0 degree |
| B. | 26.6 degree |
| C. | 90 degree |
| D. | 180 degree |
| Answer» C. 90 degree | |
| 21. |
The voltage across a 1N4001 is 0.93V when the current is 1A. What is the power dissipation of the diode for these values? |
| A. | 0.93 W |
| B. | 0.93 V |
| C. | 0.041666666666667 |
| D. | 9.3 W |
| Answer» B. 0.93 V | |
| 22. |
At cut off, the Q point is at |
| A. | upper end of the load line |
| B. | middle of the load line |
| C. | lower end of the load line |
| D. | infinity |
| Answer» D. infinity | |
| 23. |
An intrinsic semiconductor has some holes in it at room temperature. What causes these holes? |
| A. | Doping |
| B. | Valence electrons |
| C. | Free electrons |
| D. | Thermal energy |
| Answer» E. | |
| 24. |
A device that converts light energy to electrical energy is called a: |
| A. | thermocouple |
| B. | solar cell |
| C. | photodiode |
| D. | photo transistor |
| Answer» C. photodiode | |
| 25. |
To get the Norton current, you have to |
| A. | Short the load resistor |
| B. | Open the load resistor |
| C. | Short the voltage source |
| D. | Open the voltage source |
| Answer» D. Open the voltage source | |
| 26. |
In a transistor operates at the middle of the load line, an increase in the base resistance will move the Q point |
| A. | down |
| B. | up |
| C. | nowhere |
| D. | off the load line |
| Answer» B. up | |
| 27. |
A low-pass filter: |
| A. | passes lower-frequency signals and reduces higher-frequency signals |
| B. | passes higher-frequency signals and reduces lower-frequency signals |
| C. | has no effect on ac signals |
| D. | reduces the level of all frequencies by a significant amount |
| Answer» B. passes higher-frequency signals and reduces lower-frequency signals | |
| 28. |
What is the turns ratio for the transformer specified in the above question? |
| A. | 10.738 |
| B. | 0.707 |
| C. | 1.5 |
| D. | 0.575 |
| Answer» C. 1.5 | |
| 29. |
Doubling the operating frequency of an inductive circuit: |
| A. | has no effect on the inductive reactance |
| B. | doubles the amount of inductive reactance |
| C. | multiplies the inductive reactance by 6.28 |
| D. | cuts the inductive reactance in half |
| Answer» C. multiplies the inductive reactance by 6.28 | |
| 30. |
Suppose a voltage source has an ideal voltage of 12V and an internal resistance of 0.5W. For what values of load resistance will the voltage source appear stiff? |
| A. | 5 Ohm |
| B. | 50 Ohm or more |
| C. | 100 Ohm |
| D. | 6 Ohm |
| Answer» C. 100 Ohm | |
| 31. |
Which is the most widely used semiconductor? |
| A. | Copper |
| B. | Silicon |
| C. | Germanium |
| D. | All of the above |
| Answer» C. Germanium | |
| 32. |
The rotating coil of wire in an electric motor is called the: |
| A. | armature |
| B. | brush |
| C. | commutator |
| D. | loop |
| Answer» B. brush | |
| 33. |
When a parallel RLC circuit is operating at its resonant frequency: |
| A. | capacitive reactance is greater than the inductive reactance |
| B. | inductive reactance is greater than the capacitive reactance |
| C. | inductive reactance is equal to the capacitive reactance |
| D. | the difference between inductive and capacitive reactance is equal to the resistance |
| Answer» D. the difference between inductive and capacitive reactance is equal to the resistance | |
| 34. |
To get the Thevenin voltage, you have to |
| A. | Short the load resistor |
| B. | Open the load resister |
| C. | Short the voltage source |
| D. | Open the voltage source |
| Answer» B. Open the load resister | |
| 35. |
Which one of the following is a statement of Kirchhoffs current law? |
| A. | The current through a resistance is proportional to the value of resistance and the IR drop across it |
| B. | The total current in a parallel circuit is less than the value of the smallest current |
| C. | The algebraic sum of currents in a loop is equal to zero |
| D. | The algebraic sum of currents entering and leaving a point is equal to zero |
| Answer» D. The algebraic sum of currents entering and leaving a point is equal to zero | |
| 36. |
What kind of battery is most likely included in a cordless electric knife? |
| A. | Zinc-carbon battery |
| B. | Mercury-cell battery |
| C. | Nicad battery |
| D. | Lead-acid battery |
| Answer» C. Nicad battery | |
| 37. |
If N1/N2 = 2, and the primary voltage is 120 V, what is the secondary voltage? |
| A. | 0 V |
| B. | 36 V |
| C. | 40 V |
| D. | 60 V |
| Answer» E. | |
| 38. |
When a series RLC circuit is operating at its resonant frequency: |
| A. | capacitive reactance is greater than the inductive reactance |
| B. | inductive reactance is greater than the capacitive reactance |
| C. | inductive reactance is equal to the capacitive reactance |
| D. | the difference between inductive and capacitive reactance is equal to the resistance |
| Answer» D. the difference between inductive and capacitive reactance is equal to the resistance | |
| 39. |
What is the primary difference between primary and secondary cell batteries? |
| A. | Primary-cell batteries can be recharged and used many times, whereas secondary-cell batteries cannot be properly recharged |
| B. | Secondary-cell batteries can be recharged and used many times, whereas primary-cell batteries cannot be properly recharged |
| C. | Primary-cell batteries use chemical cells, whereas secondary-cell batteries use an alternative energy source, such as thermal or magnetic energy, to supplement their outputs |
| D. | Primary-cell batteries must be recharged at a much slower rate that secondary-cell batteries |
| Answer» C. Primary-cell batteries use chemical cells, whereas secondary-cell batteries use an alternative energy source, such as thermal or magnetic energy, to supplement their outputs | |
| 40. |
When applying a square waveform to a capacitor, the circuit tends to: |
| A. | peak the voltage and round off the current waveforms |
| B. | peak the current and round off the voltage waveforms |
| C. | round off both the voltage and current waveforms |
| D. | peak both the voltage and current waveforms |
| Answer» C. round off both the voltage and current waveforms | |
| 41. |
Suppose the voltage from a power outlet is 120 Vrms. What is the peak voltage? |
| A. | 100 V |
| B. | 120 V |
| C. | 170 V |
| D. | 180 V |
| Answer» D. 180 V | |
| 42. |
In a step-down transformer, which is larger? |
| A. | Primary voltage |
| B. | Secondary voltage |
| C. | Neither |
| D. | Impossible to say |
| Answer» B. Secondary voltage | |
| 43. |
Which one of the following properties of a magnetic circuit can be directly compared to resistance in an electrical circuit? |
| A. | Reluctance |
| B. | Permeability |
| C. | Permeance |
| D. | Retentivity |
| Answer» B. Permeability | |
| 44. |
What is the inductive reactance of a 0.1-H coil that is operating at 1000 Hz? |
| A. | 100 Ohm |
| B. | Less than 1 Ohm |
| C. | 628 Ohm |
| D. | 444 Ohm |
| Answer» D. 444 Ohm | |
| 45. |
A basic capacitor is composed of: |
| A. | two conductors separated by a dielectric |
| B. | two dielectrics separated by a conductor |
| C. | two coils separated by a dielectric |
| D. | two coils separated by a conductor |
| Answer» B. two dielectrics separated by a conductor | |
| 46. |
A circuit has a Norton current of 10 mA and a Norton resistance of 10 kW. What is the Thevenin circuit? |
| A. | 1000 V and a series resistance of 10 k Ohm |
| B. | 100 V and a parallel resistance of 10 k Ohm |
| C. | 100 V and a series resistance of 10 k Ohm |
| D. | 1000 V and a parallel resistance of 10 kOhm |
| Answer» D. 1000 V and a parallel resistance of 10 kOhm | |
| 47. |
Doubling the operating frequency of a purely capacitive circuit: |
| A. | has no effect on the total circuit current |
| B. | doubles the amount of total current |
| C. | cuts the total current by one-half |
| D. | thrice the amount of total current |
| Answer» C. cuts the total current by one-half | |
| 48. |
The peak value of a sine waveform is: |
| A. | the amplitude at 70.7% of the maximum value |
| B. | the amplitude at 90% of the maximum value |
| C. | the amplitude at 1.41 times the maximum value |
| D. | the maximum positive or negative value |
| Answer» E. | |
| 49. |
When the Q point moves along the load line, the voltage increases when the current |
| A. | Decreases |
| B. | Stays the same |
| C. | Increases |
| D. | Can be any of above |
| Answer» D. Can be any of above | |
| 50. |
Which one of the following statements applies to common, non-rechargeable flashlight batteries? |
| A. | Common flashlight batteries are secondary wet-cell batteries |
| B. | Common flashlight batteries are primary wet-cell batteries |
| C. | Common flashlight batteries are primary dry-cell batteries |
| D. | Common flashlight batteries are secondary dry-cell batteries |
| Answer» D. Common flashlight batteries are secondary dry-cell batteries | |