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.
| 151. |
The basic unit of measurement for current is the: |
| A. | volt |
| B. | watt |
| C. | ampere |
| D. | ohm |
| Answer» D. ohm | |
| 152. |
Doubling the diameter of the coil in an inductor: |
| A. | multiplies the value of inductance by two |
| B. | reduces the value of inductance by one-half |
| C. | reduces the value of inductance by one-fourth |
| D. | multiplies the value of inductance by four |
| Answer» B. reduces the value of inductance by one-half | |
| 153. |
Molecule is |
| A. | The smallest particle of a substance that retains the properties of that substance |
| B. | A atom that has a shortage of electrons in its outer orbit |
| C. | A atom that has an excessive number of electrons in its outer orbit |
| D. | A atom that flows whenever there is an imbalance of electrical charges between two points |
| Answer» B. A atom that has a shortage of electrons in its outer orbit | |
| 154. |
If a load resistance is 1 kW, a stiff voltage source has a resistance of |
| A. | At least 10 Ohm |
| B. | less than 10 Ohm |
| C. | More than 100 k Ohm |
| D. | Less than 100 k Ohm |
| Answer» C. More than 100 k Ohm | |
| 155. |
A battery is a device composed of one or more: |
| A. | chemical cells |
| B. | voltage generators |
| C. | solar cells |
| D. | piezoeletric cells |
| Answer» B. voltage generators | |
| 156. |
Which one of the following devices is most often used for measuring opposition to current flow in a circuit? |
| A. | Ammeter |
| B. | Voltmeter |
| C. | Ohmmeter |
| D. | Wattmeter |
| Answer» D. Wattmeter | |
| 157. |
How may valence electrons does a silicon atom have? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 4 |
| Answer» E. | |
| 158. |
Absolute Zero temperature equals |
| A. | 0o C |
| B. | -273o C |
| C. | -276o C |
| D. | 25o C |
| Answer» C. -276o C | |
| 159. |
A transistor has a current gain of 125 and a base current of 30 µA. What is the collector current? |
| A. | 3.75 mA |
| B. | 3.2 mA |
| C. | 0.05 mA |
| D. | 13 mA |
| Answer» B. 3.2 mA | |
| 160. |
Which one of the following equations most directly determines the power dissipation of a resistance when you know the voltage drop and amount of resistance? |
| A. | P = I2R |
| B. | P = IE |
| C. | P = E2/R |
| D. | I = P/E |
| Answer» D. I = P/E | |
| 161. |
What is the total resistance of a series circuit that contains four resistors having values of 220W, 470W, 1W, and 1.2W? |
| A. | 692.2 Ohm |
| B. | 844.5 Ohm |
| C. | 3890 Ohm |
| D. | 1234 Ohm |
| Answer» B. 844.5 Ohm | |
| 162. |
Which one of the following statements best applies to a parallel RLC circuit? |
| A. | The voltage waveform for each component always has the same amplitude and phase as the applied voltage |
| B. | The sum of the current is always less than the applied current |
| C. | The current waveform for each component always has the same amplitude and phase as the applied current |
| D. | All of the above |
| Answer» B. The sum of the current is always less than the applied current | |
| 163. |
Which one of the following statements best applies to a series RLC circuit? |
| A. | The voltage waveform for each component always has the same amplitude and phase as the applied voltage |
| B. | The current waveform for each component always has the same amplitude and phase as the applied current |
| C. | All of the above |
| D. | The sum of the current is always less than the applied current |
| Answer» C. All of the above | |
| 164. |
The number of free electrons and holes in intrinsic semiconductor increases when the temperature |
| A. | Decreases |
| B. | Increases |
| C. | Stays the same |
| D. | 0oC |
| Answer» C. Stays the same | |
| 165. |
Which one of the following is a direct statement of Ohm's law? |
| A. | The voltage drop across a resistance is proportional to the value of resistance and the amount of current flowing through it |
| B. | The total resistance of a parallel circuit is less than the value of the smallest resistance |
| C. | The algebraic sum of voltages in a loop is equal to zero |
| D. | The algebraic sum of currents entering and leaving a point is equal to zero |
| Answer» B. The total resistance of a parallel circuit is less than the value of the smallest resistance | |
| 166. |
A transistor has how many doped regions? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| 167. |
Household light bulbs have a given power rating, and they operate at 120 V. Which one of the following equations most directly provides the current rating of these light bulbs? |
| A. | P = I2R |
| B. | P = IE |
| C. | P = E2/R |
| D. | I = P/E |
| Answer» E. | |
| 168. |
The direction of electron current flow is: |
| A. | from right to left |
| B. | from positive to negative |
| C. | from negative to positive |
| D. | from neutral to positive |
| Answer» D. from neutral to positive | |
| 169. |
A flashlight battery has internal resistance of 1W. For what values of load resistance does the flashlight battery appear stiff? |
| A. | 60 Ohm |
| B. | 50 Ohm |
| C. | 100 Ohm or more |
| D. | 10 Ohm |
| Answer» D. 10 Ohm | |
| 170. |
The merging of a free electron and a hole is called |
| A. | Covalent bonding |
| B. | Lifetime |
| C. | Recombination |
| D. | Thermal energy |
| Answer» D. Thermal energy | |
| 171. |
Which one of the following phrases most accurately describes a purely inductive circuit? |
| A. | Resistances provide the only opposition to current flow |
| B. | Inductive reactance provides the only opposition to current flow |
| C. | Combinations of resistance and inductive reactance provide any opposition to current flow |
| D. | The ac voltage lags the current by 90 degree |
| Answer» C. Combinations of resistance and inductive reactance provide any opposition to current flow | |
| 172. |
What is the algebraic sum of this series of values:+2, -3, -6,+4? |
| A. | -6 |
| B. | -3 |
| C. | 0 |
| D. | 2 |
| Answer» C. 0 | |
| 173. |
The direction of conventional current flow is: |
| A. | from negative to positive |
| B. | from positive to negative |
| C. | from left to right |
| D. | from neutral to positive |
| Answer» C. from left to right | |
| 174. |
What is the barrier potential of a silicon diode at room temperature? |
| A. | 0.7V |
| B. | 0.3V |
| C. | 1 V |
| D. | 2 m V per degree Celsius |
| Answer» B. 0.3V | |
| 175. |
The equivalent of 1 micro A is: |
| A. | 10000A |
| B. | 1000 A |
| C. | one-millionth of an ampere |
| D. | one million amperes |
| Answer» D. one million amperes | |
| 176. |
Which one of the following statements regarding ac circuits is correct? |
| A. | Current and voltages are in phase through a resistor |
| B. | Current leads the voltage through a resistor |
| C. | Current lags the voltage through a resistor |
| D. | All of the above |
| Answer» B. Current leads the voltage through a resistor | |
| 177. |
When operating above 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» C. parallel RLC circuit operated above its resonant frequency | |
| 178. |
Suppose the zener diode has a breakdown voltage of 10 V and zener resistance of 8.5 W, what is the additional voltage when the current is 20 mA? |
| A. | 0.17 V |
| B. | 10.17 V |
| C. | 20 V |
| D. | 18.8 V |
| Answer» B. 10.17 V | |
| 179. |
The core of an electromagnet is said to be in saturation when: |
| A. | the core is permitted to move freely within the coil |
| B. | an increase in current through the coil causes no further increase in the mmf |
| C. | frequent changes in the direction of current through the coil causes heating effects in the core material |
| D. | changing the polarity of the current in the coil changes the polarity of the magnetic field around the core |
| Answer» C. frequent changes in the direction of current through the coil causes heating effects in the core material | |
| 180. |
The basic unit of measurement for resistance is the: |
| A. | volt |
| B. | ampere |
| C. | ohm |
| D. | watt |
| Answer» D. watt | |
| 181. |
Which one of the following phrasers best describes flux density? |
| A. | The concentration of lines of magnetic force |
| B. | The rate of change of the number of lines of magnetic force |
| C. | The opposition to a build-up of magnetic fields |
| D. | The force that maintains lines of force |
| Answer» B. The rate of change of the number of lines of magnetic force | |
| 182. |
What is the power dissipation of a resistance that has 24 V dropped across it and 0.25 A flowing through it? |
| A. | 3 W |
| B. | 6 W |
| C. | 64 W |
| D. | 122 W |
| Answer» C. 64 W | |
| 183. |
How much current flows through a 0.02-H choke that is operating from a 12-V ac, 100-Hz source? |
| A. | 0.02 A |
| B. | 0.955 A |
| C. | 0.41666666666667 |
| D. | 2.02 A |
| Answer» C. 0.41666666666667 | |
| 184. |
What is a negative ion? |
| A. | An atom that contains more electrons than neutrons |
| B. | An atom that contains more protons than neutrons |
| C. | An atom that contains more electrons than protons |
| D. | An atom that contains more protons than electrons |
| Answer» D. An atom that contains more protons than electrons | |
| 185. |
Which one of the following statements is true for current flowing in a series circuit? |
| A. | The amount of current flow through each part of a series circuit can be different, depending on the resistance of each part and the amount of voltage applied to it |
| B. | The total current in a series circuit is equal to the sum of the currents flowing through the individual components in the circuit |
| C. | The same current flows through every part of a series circuit |
| D. | The total current in a series circuit is equal to the total voltage multiplied by the total resistance |
| Answer» D. The total current in a series circuit is equal to the total voltage multiplied by the total resistance | |
| 186. |
The net charge of a neutral copper atom is |
| A. | 0 |
| B. | 1 |
| C. | -1 |
| D. | 4 |
| Answer» C. -1 | |
| 187. |
Holes are the minority carriers in which type of semiconductor? |
| A. | Extrinsic |
| B. | Intrinsic |
| C. | n-type |
| D. | p-type |
| Answer» D. p-type | |
| 188. |
What is the capacitive reactance of a 0.1 micro F capacitor that is operating at 1000 Hz? |
| A. | less than 1 Ohm |
| B. | 1590 Ohm |
| C. | 312 Ohm |
| D. | 690 Ohm |
| Answer» C. 312 Ohm | |
| 189. |
The north pole of a magnet is the one: |
| A. | that has its molecules arranged in a random pattern |
| B. | that would be attracted to the earth's north magnetic pole |
| C. | that would be repelled by the south pole of another magnet |
| D. | that would be attracted to the earth's south magnetic pole |
| Answer» C. that would be repelled by the south pole of another magnet | |
| 190. |
Reducing the amount of current through an inductor: |
| A. | reduces the value of inductance by one-half |
| B. | multiplies the value of inductance by four |
| C. | multiplies the value of inductance by two |
| D. | has no effect on the inductance |
| Answer» E. | |
| 191. |
Which one of the following statements is true for resistance in a parallel circuit? |
| A. | The total resistance is equal to the sum of the individual resistances in a parallel circuit. |
| B. | The total resistance of a parallel circuit is always less than the value of the smallest resistance |
| C. | The total resistance of a parallel circuit is equal to the total voltage |
| D. | The total resistance in a parallel circuit is equal to the average value of the individual resistances |
| Answer» C. The total resistance of a parallel circuit is equal to the total voltage | |
| 192. |
The secondary voltage for a certain power transformer is twice the voltage applied to the primary. The current flowing in the secondary winding will be: |
| A. | One-half the primary current |
| B. | Same as the primary current |
| C. | Twice the primary current |
| D. | No more than 10% less than the primary current |
| Answer» B. Same as the primary current | |
| 193. |
Holes act like: |
| A. | Atoms |
| B. | Crystals |
| C. | Negative charges |
| D. | Positive charges |
| Answer» E. | |
| 194. |
Which one of the following phrases best describes residual magnetism? |
| A. | Magnetism that remains in the core of an electromagnet after the current through the coil is turned off |
| B. | The force of attraction between the poles of a permanent and temporary magnetic field |
| C. | The amount of magnetic flux that is not confined to the core material of an electromagnet |
| D. | The circular magnetic field that surrounds a conductor carrying a current |
| Answer» B. The force of attraction between the poles of a permanent and temporary magnetic field | |
| 195. |
The total capacitance of a series capacitor circuit is: |
| A. | equal to the sun of the individual capacitive-reactance values |
| B. | equal to the sum of the individual capacitance values |
| C. | equal to the source voltage divided by total current |
| D. | less than the value of the smallest capacitor |
| Answer» E. | |
| 196. |
The transistor has a collector current of 10 mA and a base current of 40 mA. What is the current gain of the transistor? |
| A. | 250 μA |
| B. | 350 μA |
| C. | 0.25 μA |
| D. | 300 μA |
| Answer» B. 350 ŒºA | |
| 197. |
When the graph of current versus voltage is a straight line, the device is referred to as |
| A. | Active |
| B. | Linear |
| C. | Nonlinear |
| D. | Bipolar |
| Answer» C. Nonlinear | |
| 198. |
What is a free electron? |
| A. | An electron that has been freed from its parent atom |
| B. | An electron that costs nothing |
| C. | An electron that has no electrical charge |
| D. | An electron that has twice the amount of charge of a normal electron |
| Answer» B. An electron that costs nothing | |
| 199. |
If the base supply voltage increases, the Q point moves |
| A. | down |
| B. | up |
| C. | nowhere |
| D. | off the load line |
| Answer» B. up | |
| 200. |
What form of energy is used to maintain an imbalance of charges between the terminals of a battery? |
| A. | Electronical energy |
| B. | Mechanical energy |
| C. | Chemical energy |
| D. | Solar energy |
| Answer» D. Solar energy | |