|
| 1 | In series circuits XL is at 90° and XC is at 90°, which will always be the same phase angles. |
 | A) | True |
| B) | False |
|
| 2 | In a resistor, V and I are always in phase. |
| A) | True |
| B) | False |
|
| 3 | XL is a phasor quantity with a 180° phase angle. |
| A) | True |
| B) | False |
|
| 4 | For series inductors, the voltage drops cannot be added algebraically, since each voltage drop has a different phase relationship with respect to the series current. |
| A) | True |
| B) | False |
|
| 5 | With regard to the phase angle for the capacitive reactance, the voltage across any XC always lags its capacitive charge and discharge current by 90°. |
| A) | True |
| B) | False |
|
| 6 | Exactly opposite reactive branch currents are 90° out of phase with each other. |
| A) | True |
| B) | False |
|
| 7 | The impedance angle of a series circuit is the angle whose tangent equals R/X. |
| A) | True |
| B) | False |
|
| 8 | In general, when the series resistance and reactance are equal, ZT is 0.707 times either value. |
| A) | True |
| B) | False |
|
| 9 | In a parallel circuit, θ is the angle whose tangent is IX/IR. |
| A) | True |
| B) | False |
|
| 10 | Resistive power that is dissipated as heat is power. |
|
| 11 | Unity power factor means a circuit. |
|
| 12 | When V and I are out of phase because of reactance, the product of V times I is called power. |
|
| 13 | Volt-amperes at the angle of 90° are called . |
|
| 14 | In order to realize efficient distribution of electric power in commercial applications, the power factor should be close to . |
|
| 15 | A combination of resistance and reactance is . |
|
| 16 | The real power in can be calculated as I2R. |
|
| 17 | All analog ac meters have scales calibrated in values unless noted otherwise on the meter. |
|
| 18 | In a circuit with resistance and reactance, real power can be calculated as |
| A) | IR |
| B) | VI |
| C) | VI cos θ |
| D) | R2I |
|
| 19 | What is a numerical ratio with a value between 0 and 1 that is equal to the cosine of the phase angle? |
| A) | reactance factor |
| B) | power factor |
| C) | resistance factor |
| D) | phase factor |
|
| 20 | Which of the following meter movements will not read properly in an ac circuit? |
| A) | thermal type |
| B) | electromagnetic type |
| C) | D'Arsonval type |
| D) | rectifier type |
|
| 21 | The wattmeter is an example of what type meter movement? |
| A) | rectifier type |
| B) | thermal type |
| C) | electromagnetic type |
| D) | D'Arsonval type |
|
| 22 | Which of the following is not affected by changing frequencies? |
| A) | resistance |
| B) | inductive reactance |
| C) | capacitive reactance |
| D) | impedance |
|
| 23 | In a resistor |
| A) | V leads I |
| B) | I leads V |
| C) | V and I are always in phase |
| D) | V and I are never in phase |
|
| 24 | XL is a phasor quantity with a |
| A) | 45° phase angle |
| B) | 90° phase angle |
| C) | 0° phase angle |
| D) | 180° phase angle |
|
| 25 | In using double subscripts, the first letter in the subscript is the |
| A) | ground reference |
| B) | point of measurement with respect to the second letter |
| C) | out of phase reference |
| D) | in phase reference |