Title: Final
Course: Electrical Theory (IC 101-IC 101) > Section: Assessments

Q: A sine wave of 250K Hz has a period of 4 microseconds.
- True
- False
A: True

Q: Frequency is = the distance of one complete cycle.
- True
- False
A: False

Q: Inductive reactance varies directly as the frequency varies.
- True
- False
A: True

Q: The voltage and turns ratio of a transformer are inversely proportional.
- True
- False
A: False

Q: There is a large amount of electron flow through the dielectric of a capacitor when you apply an AC signal.
- True
- False
A: False

Q: A transformer with no losses has a 120 volt supply with 5 amps in the primary, with 250 volts output in the secondary. What is the secondary current?
- 2 amps
- 10 amps
- 12.3 amps
- 2.4 amps
- 3.68 amps
A: 2 amps

Q: If a parallel circuit is open in the main line, the current
- Increases in each branch
- Is zero in all the branches
- Is zero only in the branch that has the highest resistance
- Increases in the branch that has the lowest resistance
A: Increases in each branch

Q: If 6.25x10^18 electrons pass through a 1000 Ohm resistor in one second, the amount of power dissipated in that resistance is^
- 625 milliwatts
- 1000 watts
- 6.25K watts
- 1 watt
A: 625 milliwatts

Q: In a circuit with three parallel branches, if one branch opens, the main line current will be
- More
- Less
- The same
- Infinite
A: More

Q: In a parallel bank with unequal branch resistance
- The current is highest in the highest resistance
- The current is equal in all the branches
- The voltage is highest across the lowest resistance
- The current is highest in the lowest resistance
A: The current is highest in the highest resistance

Q: In a series circuit with unequal resistances
- The lowest resistance has the highest voltage
- The highest resistance has the highest voltage
- The lowest resistance has the most current
- The highest resistance has the most current
A: The lowest resistance has the highest voltage

Q: In a three-phase circuit, the apparent power can be computed using this formula: VA = volts times ______ times the square root of three.
- Amps
- Resistance
- Inductance
- Capacitance
A: Amps

Q: In motor circuits, the reactance is primarily.
- Inductive
- Resistive
- Capacitive
- AC
A: Inductive

Q: One cycle of a sine wave voltage corresponds to:
- 45 degrees
- 90 degrees
- 180 degrees
- 360 degrees
- A cycle of sine wave cannot be express in degrees
A: 45 degrees

Q: The amount of capacitance needed can be determined by connecting a(n) ________, ammeter, and voltmeter to the circuit.
- Coulometer
- Megohmmeter
- Wattmeter
- Ohmmeter
A: Coulometer

Q: The amount of opposition due to inductance, called inductive reactance, depends upon the amount of inductance present and the ___________ of the ac system.
- Temperature
- Volume
- Frequency
- Area
A: Temperature

Q: The frequency of a sine wave voltage is 500K Hz. What is the period of the voltage?
- 2μ seconds
- 20μ seconds
- 50μ seconds
- 500μ seconds
A: 2μ seconds

Q: The power factor is determined by the _________ of the angle between the voltage and the current.
- Cosine
- Sine
- Tangent
- Cosecant
A: Cosine

Q: The sum of series voltage drops
- Is less than the smallest voltage drop
- Equals the average value of all the voltage drops
- Equals the applied voltage
- Is usually more than the applied voltage
A: Is less than the smallest voltage drop

Q: The type of capacitor that requires polarity considerations when connected to a circuit is the:
- Electrolytic
- Mica
- Paper
- Oil
- Fared
A: Electrolytic

Q: The unit of potential difference is the
- Coulomb
- Ampere
- Volt
- Ohm
- Mho
A: Coulomb

Q: The value of the voltage across an inductor is 300 volts. If the reactance of the inductor is 30K Ohms, what is the value of the current through the inductor?
- 0.1mA
- 1mA
- 10mA
- 100mA
- None of the above
A: 0.1mA

Q: When one resistance in a series string is open
- The current is maximum in the normal resistances
- The current is zero in all the resistances
- The voltage is zero across the open resistance
- The current increases in the voltage source
A: The current is maximum in the normal resistances

Q: When two resistances are connected in series
- They must both have the same resistance value
- The voltage across each must be the same
- They must have different resistance values
- There is only one path for current through both resistances
A: They must both have the same resistance value

Q: When two resistances are connected in parallel
- The current through each must be the same
- The voltage across each must be the same
- Their combined resistance equals the sum o the individual resistors
- Each must have the same resistance value
A: The current through each must be the same

Q: With 100 volts applied across a 10K Ohm resistance, the power dissipation equals
- 1m Watt
- 1 Watt
- 100 Watts
- 1K Watt
A: 1m Watt

Q: With resistances of 100, 200, 300, 400, and 500 Ohms in parallel, the total resistance is
- Less than 100 Ohms
- More than 1M Ohm
- About 500 Ohms
- About 1K Ohm
A: Less than 100 Ohms

Q: A 10μfd, 20μfd, and 50μfd capacitor are in parallel, What is the total capacitance of the circuit?
A: 80microfarad

Q: An AC circuit with three 100 Ohm resistors in series has a total resistance of ________ Ohms.
A: 300

Q: f = 1.5K HZ                C = 12μfd                    X_C = ___________
A: 8.842 Ohms

Q: What is the RC time constant for a 2M Ohm resistor in series with a 2μfd capacitor?
A: 4 sec

Q: With 10 Ohms X_Lin series with 10 Ohms of resistance, the total impedance equals _______ Ohms.
A: 14.142 Ohms

Q: X_L = ___________                 f = 150K Hz              L = 10mH
A: 9425 Ohms

Q: V_1=
A: 400V

Q: V_2=
A: 200V

Q: V_3=
A: 100V

Q: What is the instantaneous value at 50° of the cycle?
A: 20.797V

Q: What is the peak value?
A: 27.149V

Q: P_3=
A: 100mW

Q: P_4=
A: 60mW

Q: R_2=
A: 600 Ohms

Q: V_1=
A: 4V

Q: V_T=
A: 24V

Q: I_2=
A: 1.455A

Q: P_1=
A: 6.54W

Q: P_2=
A: 17.46W

Q: P_3=
A: 24W

Q: R_T=
A: 3 Ohms

Q: I_3=
A: 30mA

Q: I_5=
A: 7.5mA

Q: I_T=
A: 30mA

Q: V_1=
A: 5.4V

Q: V_2=
A: 22.5V

Q: I_C=
A: 4mA

Q: I_R=
A: 4.5mA

Q: I_T=
A: 6.02mA

Q: Z_T=
A: 5.98K Ohms

Q: θ=
A: 41.6 degrees

Q: V_L=
A: 12.012V

Q: V_R=
A: 8.985V

Q: X_L=
A: 628.3 Ohms

Q: Z_T=
A: 784.64 Ohms

Q: θ=
A: 53.2 degrees

Q: How many capacitive VAR's would be needed to correct the power factor to 98%.
A: 2416 VAR

Q: What is the power factor?
A: .80