MCQOPTIONS
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MCQOPTIONS
This section includes 231 Mcqs, each offering curated multiple-choice questions to sharpen your Computer Science knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Who invented the first junction transistor? |
| A. | Smith |
| B. | Gomes |
| C. | Fisher |
| D. | Shockley |
| Answer» E. | |
| 102. |
If the current gain is 200 and the collector current is 100 mA, the base current is |
| A. | 2 mA |
| B. | 0.5 mA |
| C. | 0.083333333333333 |
| D. | 200 A |
| Answer» C. 0.083333333333333 | |
| 103. |
Current is |
| A. | The flow of charged particles through a material |
| B. | An imbalance of electrical charges |
| C. | The force that causes electrons to flow |
| D. | The number of free electrons in an atom |
| Answer» B. An imbalance of electrical charges | |
| 104. |
A typical light switch in your home is a: |
| A. | knife switch |
| B. | toggle switch |
| C. | rotary switch |
| D. | momentary push button switch |
| Answer» C. rotary switch | |
| 105. |
Silicon atoms combine into an orderly pattern called a |
| A. | Crystal |
| B. | Covalent bond |
| C. | Semiconductor |
| D. | Valence orbit |
| Answer» B. Covalent bond | |
| 106. |
The Thevenin resistance is equal in value to the |
| A. | Load resistance |
| B. | Half the load resistance |
| C. | Internal resistance of a Morton circuit |
| D. | Open-load resistance |
| Answer» B. Half the load resistance | |
| 107. |
The saturation point is approximately the same as |
| A. | cutoff point |
| B. | lower end of the load line |
| C. | upper end of the load line |
| D. | infinity |
| Answer» D. infinity | |
| 108. |
The barrier potential accross each depletion layer is |
| A. | 0 |
| B. | 0.8 V |
| C. | 0.7 V |
| D. | 20 V |
| Answer» D. 20 V | |
| 109. |
How much current flows through a 60-W light bulb that is operating at 120 V? |
| A. | 0.5A |
| B. | 180 A |
| C. | 0.083333333333333 |
| D. | 7200 A |
| Answer» B. 180 A | |
| 110. |
Which one of the following kinds of materials has the highest permeability? |
| A. | A diamagnetic material |
| B. | A ferromagnetic material |
| C. | A paramagnetic material |
| D. | All of the above |
| Answer» C. A paramagnetic material | |
| 111. |
Which one of the following statements is true for the voltage in a parallel RL 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 inductance |
| C. | The total voltage lags the total current by less than 90 |
| D. | The total voltages is less than the sum of the voltages across the resistance and inductance |
| Answer» B. The total voltage is equal to the sum of the voltages across the resistance and inductance | |
| 112. |
The Norton current is sometimes called the |
| A. | Shorted-load current |
| B. | Open-load current |
| C. | Thevenin current |
| D. | Thevenin voltage |
| Answer» B. Open-load current | |
| 113. |
At room temperature a conductor has low many holes? |
| A. | Same number as free electrons |
| B. | many |
| C. | Only those produced by thermal energy |
| D. | less than the free electrons |
| Answer» B. many | |
| 114. |
Most AC power is obtained from: |
| A. | generators |
| B. | batteries |
| C. | oscillators |
| D. | lightning |
| Answer» D. lightning | |
| 115. |
Determine the resistance value and tolerance of a resistor that has the following color bands; first band is red, second band is red, third band is orange, and the fourth band is gold |
| A. | 220 Ohm, 5% |
| B. | 220 Ohm, 10% |
| C. | 22,000 Ohm, 5% |
| D. | 22, 000 Ohm, 10% |
| Answer» D. 22, 000 Ohm, 10% | |
| 116. |
A step-down transformer has turns ration of 5:1. If the primary voltage is 120 Vrms, what is the secondary voltage? |
| A. | 12 V |
| B. | 18 V |
| C. | 24 V |
| D. | 30 V |
| Answer» D. 30 V | |
| 117. |
Electron current is flowing through a conductor in a direction you might describe as straight into this page. What is the direction of the resulting magnetic field? |
| A. | Clockwise |
| B. | Counterclockwise |
| C. | Out of this page |
| D. | Into this page |
| Answer» C. Out of this page | |
| 118. |
Which one of the following equations most directly determines the amount of current flowing through a resistor when you know the value of the resistor and the voltage drop across it? |
| A. | E = PR |
| B. | E = I2R |
| C. | I = E/R |
| D. | I = ER |
| Answer» D. I = ER | |
| 119. |
When operating below its resonant frequency, a parallel RLC circuit has the characteristics of a: |
| A. | parallel RL circuit |
| B. | parallel RC circuit |
| C. | parallel RLC circuit operated above its resonant frequency |
| D. | purely resistive circuit |
| Answer» B. parallel RC circuit | |
| 120. |
A loadstone is: |
| A. | a natural magnet |
| B. | a temporary magnet |
| C. | an artificial magnet |
| D. | a paramagnetic alloy |
| Answer» B. a temporary magnet | |
| 121. |
Which one of the following is most likely used for measuring the rate of electron flow? |
| A. | Voltmeter |
| B. | Ammeter |
| C. | Wattmeter |
| D. | Ohmmeter |
| Answer» C. Wattmeter | |
| 122. |
A zener diode has a voltage of 10 V and a current of 20 mA. What is the power dissipation? |
| A. | 200 mW |
| B. | 300 mW |
| C. | 20 mW |
| D. | 10 mW |
| Answer» B. 300 mW | |
| 123. |
Suppose a step-down transformer has a turns ration of 5:1. If the secondary current is 1A rms, what is the primary-current? |
| A. | 0.3 A |
| B. | 0.2 A |
| C. | 0.4 A |
| D. | 0.6 A |
| Answer» C. 0.4 A | |
| 124. |
Which one of the following statements is true for voltage in a series circuit? |
| A. | The total voltage is equal to the sum of the individual voltages in a series circuit |
| B. | The total voltage in a series circuit is equal to the average value of the individual voltages |
| C. | The total voltage of a series circuit is equal to the total current divided by the total resistance |
| D. | The total voltage in a series circuit is always less than the value of the smallest voltage |
| Answer» B. The total voltage in a series circuit is equal to the average value of the individual voltages | |
| 125. |
What is the turns ratio of a power transformer that shows 50 V at its secondary winding when you apply 150 V to its primary winding? |
| A. | 43556 |
| B. | 43525 |
| C. | 2 |
| D. | 3 |
| Answer» E. | |
| 126. |
Which one of the following statements most accurately reflects the nature of ac power? |
| A. | The current in an ac circuit flows in one direction, but changes value periodically |
| B. | The current in an ac circuit flows in one direction at a steady level |
| C. | The current in an ac circuit changes direction periodically |
| D. | The current in an ac circuit flows in two directions at the same time |
| Answer» D. The current in an ac circuit flows in two directions at the same time | |
| 127. |
Doubling the operating frequency of a capacitive circuit: |
| A. | doubles the amount of a capacitive reactance |
| B. | has no effect on the capacitive reactance |
| C. | cuts the capacitive reactance in half |
| D. | multiplies the capacitive reactance by 6.28 |
| Answer» D. multiplies the capacitive reactance by 6.28 | |
| 128. |
When operating below 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 above its resonant frequency |
| D. | purely resistive circuit |
| Answer» C. series RLC circuit operated above its resonant frequency | |
| 129. |
Which one of the following statements is true for the currents in a parallel RL circuit? |
| A. | The total current is equal to the sum of the currents through the resistance and inductance |
| B. | The current always has the same amplitude and phase for every part of the circuit |
| C. | The total current is less than the sum of the currents through the resistance and inductance |
| D. | The total current leads the total voltage by less than 90 |
| Answer» D. The total current leads the total voltage by less than 90 | |
| 130. |
A device that converts chemical energy to electrical energy is called a: |
| A. | solar cell |
| B. | thermocouple |
| C. | chemical cell |
| D. | electric device |
| Answer» D. electric device | |
| 131. |
Doubling the number of turns of wire in an inductor: |
| A. | reduces the value of inductance by one-half |
| B. | multiplies the value of inductance by two |
| C. | multiplies the value of inductance by four |
| D. | reduces the value of inductance by one-fourth |
| Answer» D. reduces the value of inductance by one-fourth | |
| 132. |
Which one of the following statements is true for voltage in a parallel circuit? |
| A. | The total voltage in a parallel circuit is equal to the average value of the individual voltages |
| B. | The total voltage in a parallel circuit is always less than the value of the smallest voltage |
| C. | The total voltage is equal to the sum of the voltages across the individual branches in a parallel circuit |
| D. | The total voltage of a parallel circuit is the same as the voltages across each branch |
| Answer» E. | |
| 133. |
Doubling the operating voltage of a purely capacitive circuit: |
| A. | has no effect on the capacitive reactance |
| B. | doubles the amount of capacitive reactance |
| C. | multiplies the capacitive reactance by 7 |
| D. | cuts the capacitive reactance in half |
| Answer» B. doubles the amount of capacitive reactance | |
| 134. |
Doubling the operating frequency of a purely inductive circuit: |
| A. | doubles the amount of current through the inductors |
| B. | has no effect on the current through the inductors |
| C. | cuts the current through the inductors one-half |
| D. | increases the current, but by an amount that can be determined only by doing a complete analysis of the circuit |
| Answer» D. increases the current, but by an amount that can be determined only by doing a complete analysis of the circuit | |
| 135. |
Which one of the following statements is true for the currents in a parallel RC circuit? |
| A. | The total current is equal to the sum of the currents for the resistance and capacitance |
| B. | The current always has the same amplitude and phase for every part of the circuit |
| C. | The total current is less than the sum of the currents for the resistance and capacitance |
| D. | The total current. is greater than the sum of the currents for the resistance and capacitance |
| Answer» B. The current always has the same amplitude and phase for every part of the circuit | |
| 136. |
Which one of. the following phrases most accurately describes the nature of a pulsating dc voltage? |
| A. | The voltage remains at one polarity and at a steady level |
| B. | The voltage remains at one polarity but changes value periodically |
| C. | The voltage causes current to flow in two directions at the same time |
| D. | The voltage reverses polarity periodically |
| Answer» C. The voltage causes current to flow in two directions at the same time | |
| 137. |
Which one of the following equations most directly leads to the resistance of an ordinary household light bulb, assuming that you know the power and voltage rating? |
| A. | R = E2/P |
| B. | P = PR |
| C. | P = E2/R |
| D. | I = P/E |
| Answer» B. P = PR | |
| 138. |
One henry of inductance is defined as: |
| A. | the amount of counter emf required to reduce a current to 1 A |
| B. | the amount of inductance required for generating 1 V of counter emf when the current changes at the rate of 1 A per second |
| C. | the amount of inductance required to change the frequency of a current by 1 Hz |
| D. | the number of turns of wire in an inductor multiplied by the amount of current flowing through it |
| Answer» C. the amount of inductance required to change the frequency of a current by 1 Hz | |
| 139. |
Which one of the following statements is true for the currents in a series RC circuit? |
| A. | The current always has the same amplitude and phase for every part of the circuit |
| B. | The total current is equal to the sum of the currents for the resistance and capacitance |
| C. | The total current is greater than the sum of the currents for the resistance and capacitance |
| D. | The total current is less than the sum of the currents for the resistance and capacitance |
| Answer» B. The total current is equal to the sum of the currents for the resistance and capacitance | |
| 140. |
When the collector current increases, what does the current gain do? |
| A. | decreases |
| B. | stays the same |
| C. | increases |
| D. | any of the above |
| Answer» D. any of the above | |
| 141. |
The value of a capacitor can be made larger by: |
| A. | increasing the area of the plates |
| B. | decreasing the area of the plates |
| C. | increasing the frequency of the applied voltage |
| D. | increasing the voltage applied to the plates |
| Answer» B. decreasing the area of the plates | |
| 142. |
A farad is defined as the amount of capacitance necessary for: |
| A. | dissipating 1 W of power |
| B. | causing an ac phase shift greater than 90 degree |
| C. | storing 1 V for 1 second |
| D. | changing the voltage on the plates at the rate of 1 V per second when 1 A of current is flowing |
| Answer» E. | |
| 143. |
Waveforms are graphs that show: |
| A. | frequency on the vertical axis and amplitude on the horizontal axis |
| B. | amplitude on the vertical axis and frequency on the horizontal axis |
| C. | amplitude on the vertical axis and the passage of time on the horizontal axis |
| D. | the passage of time on the vertical axis and amplitude on the horizontal axis |
| Answer» D. the passage of time on the vertical axis and amplitude on the horizontal axis | |
| 144. |
Which one of the following principles best describes the basic operation of a generator? |
| A. | Like magnetic poles repel; unlike poles attract |
| B. | Current is induced in a conductor that is moving through a magnetic field |
| C. | Like magnetic poles attract; unlike poles repel |
| D. | Current flowing through a conductor generates a magnetic field |
| Answer» C. Like magnetic poles attract; unlike poles repel | |
| 145. |
A high-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. | increases the level of all frequencies by a significant amount |
| Answer» C. has no effect on ac signals | |
| 146. |
In a pure inductor: |
| A. | ac current leads the voltage by 90 degree |
| B. | ac current and voltage are exactly in phase |
| C. | ac current lags the voltage by 90 degree |
| D. | ac current is converted to dc voltage |
| Answer» D. ac current is converted to dc voltage | |
| 147. |
Which one of the following statements is true for the impedance of a series RC circuit? |
| A. | The impedance is greater than the sum of the resistance and capacitive reactance |
| B. | The impedance is equal to the sum of the resistance and capacitive reactance |
| C. | The impedance is greater than either the resistance or capacitive reactance but less than their sum |
| D. | The impedance is less than the sum of the resistance and capacitive reactance |
| Answer» D. The impedance is less than the sum of the resistance and capacitive reactance | |
| 148. |
A zener regulator has an input voltage from 15 to 20 V and a load current from 5 to 20 mA. If the zener voltage is 6.8 V, what value should the series resistor have? |
| A. | 310 Ohm |
| B. | 400 Ohm |
| C. | 410 Ohm |
| D. | 550 Ohm |
| Answer» D. 550 Ohm | |
| 149. |
A transformer has a primary voltage of 120 V rms and a secondary voltage of 25 V rms. If the secondary current is 1A rms, what is the primary current? |
| A. | 7.8 mA |
| B. | 208 mA |
| C. | 200 mA |
| D. | 300 mA |
| Answer» C. 200 mA | |
| 150. |
What is the smallest number of polarities required for current flow? |
| A. | One - a negative terminal |
| B. | Two - a negative terminal and a positive terminal |
| C. | Three - negative, positive and neutral terminals |
| D. | Four - two negative and two positive |
| Answer» C. Three - negative, positive and neutral terminals | |