How many questions are in subelement G5?

The current pool contains 40 questions in subelement G5.

general pool

Subelement G5 question review

All 40 official questions with the exact winning phrase marked.

G5A01G5A

What happens when inductive and capacitive reactance are equal in a series LC circuit?

CResonance causes impedance to be very low

G5A02G5A

What is reactance?

BOpposition to the flow of alternating current caused by capacitance or inductance

G5A03G5A

Which of the following is opposition to the flow of alternating current in an inductor?

DReactance

Why this answer

The key fact is Reactance. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: Inductors store energy in a magnetic field.

E = I × R

G5A04G5A

Which of the following is opposition to the flow of alternating current in a capacitor?

CReactance

Why this answer

The key fact is Reactance. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: Capacitors store energy in an electric field.

E = I × R

G5A05G5A

How does an inductor react to AC?

DAs the frequency of the applied AC increases, the reactance increases

G5A06G5A

How does a capacitor react to AC?

AAs the frequency of the applied AC increases, the reactance decreases

G5A07G5A

What is the term for the inverse of impedance?

DAdmittance

G5A08G5A

What is impedance?

CThe ratio of voltage to current

G5A09G5A

What unit is used to measure reactance?

BOhm

G5A10G5A

Which of the following devices can be used for impedance matching at radio frequencies?

DAll these choices are correct

G5A11G5A

What letter is used to represent reactance?

G5A12G5A

What occurs in an LC circuit at resonance?

DInductive reactance and capacitive reactance cancel

G5B01G5B

What dB change represents a factor of two increase or decrease in power?

BApproximately 3 dB

Why this answer

The key fact is Approximately 3 dB. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

P = E × I

G5B02G5B

How does the total current relate to the individual currents in a circuit of parallel resistors?

CIt equals the sum of the currents through each branch

Why this answer

Use this action or method: It equals the sum of the currents through each branch. It is the choice that directly completes the job described in the question.

E = I × R

G5B03G5B

How many watts of electrical power are consumed if 400 VDC is supplied to an 800-ohm load?

B200 watts

Why this answer

The required value is 200 watts. Keep the units with the number so a nearby distractor cannot pull you away from the result.

E = I × R

G5B04G5B

How many watts of electrical power are consumed by a 12 VDC light bulb that draws 0.2 amperes?

A2.4 watts

Why this answer

The required value is 2.4 watts. Keep the units with the number so a nearby distractor cannot pull you away from the result.

P = E × I

G5B05G5B

How many watts are consumed when a current of 7.0 milliamperes flows through a 1,250-ohm resistance?

AApproximately 61 milliwatts

Why this answer

The required value is Approximately 61 milliwatts. Keep the units with the number so a nearby distractor cannot pull you away from the result.

E = I × R

G5B06G5B

What is the PEP produced by 200 volts peak-to-peak across a 50-ohm dummy load?

B100 watts

Why this answer

The key fact is 100 watts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5B07G5B

What value of an AC signal produces the same power dissipation in a resistor as a DC voltage of the same value?

CThe RMS value

Why this answer

The required value is The RMS value. Keep the units with the number so a nearby distractor cannot pull you away from the result.

E = I × R

G5B08G5B

What is the peak-to-peak voltage of a sine wave with an RMS voltage of 120 volts?

D339.4 volts

Why this answer

The key fact is 339.4 volts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5B09G5B

What is the RMS voltage of a sine wave with a value of 17 volts peak?

B12 volts

Why this answer

The key fact is 12 volts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5B10G5B

What percentage of power loss is equivalent to a loss of 1 dB?

C20.6 percent

Why this answer

The key fact is 20.6 percent. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

P = E × I

G5B11G5B

What is the ratio of PEP to average power for an unmodulated carrier?

B1.00

Why this answer

The key fact is 1.00. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

P = E × I

G5B12G5B

What is the RMS voltage across a 50-ohm dummy load dissipating 1200 watts?

B245 volts

Why this answer

The key fact is 245 volts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5B13G5B

What is the output PEP of an unmodulated carrier if the average power is 1060 watts?

B1060 watts

Why this answer

The key fact is 1060 watts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

P = E × I

G5B14G5B

What is the output PEP of 500 volts peak-to-peak across a 50-ohm load?

B625 watts

Why this answer

The key fact is 625 watts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5C01G5C

What causes a voltage to appear across the secondary winding of a transformer when an AC voltage source is connected across its primary winding?

CMutual inductance

Why this answer

The key fact is Mutual inductance. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5C02G5C

What is the output voltage if an input signal is applied to the secondary winding of a 4:1 voltage step-down transformer instead of the primary winding?

AThe input voltage is multiplied by 4

Why this answer

The key fact is The input voltage is multiplied by 4. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5C03G5C

What is the total resistance of a 10-, a 20-, and a 50-ohm resistor connected in parallel?

A5.9 ohms

Why this answer

The key fact is 5.9 ohms. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5C04G5C

What is the approximate total resistance of a 100- and a 200-ohm resistor in parallel?

D67 ohms

Why this answer

The required value is 67 ohms. Keep the units with the number so a nearby distractor cannot pull you away from the result.

E = I × R

G5C05G5C

Why is the primary winding wire of a voltage step-up transformer usually a larger size than that of the secondary winding?

BTo accommodate the higher current of the primary

Why this answer

The reason is to accommodate the higher current of the primary. Connect the cause in the question to this direct result instead of memorizing the answer letter.

E = I × R

G5C06G5C

What is the voltage output of a transformer with a 500-turn primary and a 1500-turn secondary when 120 VAC is applied to the primary?

A360 volts

Why this answer

The key fact is 360 volts. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

E = I × R

G5C07G5C

What transformer turns ratio matches an antenna’s 600-ohm feed point impedance to a 50-ohm coaxial cable?

A3.5 to 1

Why this answer

The key fact is 3.5 to 1. Match that fact to the exact condition in the question; the other choices describe a different rule, band, component, or operating situation.

Memory hook: A half wave dipole is two quarter wave legs.

E = I × R

G5C08G5C

What is the equivalent capacitance of two 5.0-nanofarad capacitors and one 750-picofarad capacitor connected in parallel?

D10.750 nanofarads

G5C09G5C

What is the capacitance of three 100-microfarad capacitors connected in series?

C33.3 microfarads

G5C10G5C

What is the inductance of three 10-millihenry inductors connected in parallel?

C3.3 millihenries

G5C11G5C

What is the inductance of a circuit with a 20-millihenry inductor connected in series with a 50-millihenry inductor?

C70 millihenries

G5C12G5C

What is the capacitance of a 20-microfarad capacitor connected in series with a 50-microfarad capacitor?

B14.3 microfarads

G5C13G5C

Which of the following components should be added to a capacitor to increase the capacitance?

CA capacitor in parallel

G5C14G5C

Which of the following components should be added to an inductor to increase the inductance?

DAn inductor in series