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Subelement B-005

B-005

Section B-005-004

Section B-005-004

What is the voltage across a 2-ohm resistor if a current of 0.5 amperes flows through it?

  • 1.5 volts
  • 0.25 volts
  • 2.5 volts
  • Correct Answer
    1.0 volts

Ohm's Law ( I = E / R ) becomes E = R*I when solving for E. Voltage = resistance times current. Volts = ohms * amperes. 2 ohms * 0.5 amperes = 1.0 volts.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

How is the current in a DC circuit calculated when the voltage and resistance are known?

  • Current equals resistance multiplied by voltage
  • Current equals resistance divided by voltage
  • Correct Answer
    Current equals voltage divided by resistance
  • Current equals power divided by voltage

Ohm's Law is I = E / R, current is voltage divided by resistance. Amperes = volts / ohms.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

How is the resistance in a DC circuit calculated when the voltage and current are known?

  • Correct Answer
    Resistance equals voltage divided by current
  • Resistance equals current divided by voltage
  • Resistance equals power divided by voltage
  • Resistance equals current multiplied by voltage

Ohm's Law ( I = E / R ) becomes R = E / I when solving for R. Resistance is voltage divided by current. Ohms = volts / amperes.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

How is the voltage in a DC circuit calculated when the current and resistance are known?

  • Voltage equals power divided by current
  • Correct Answer
    Voltage equals current multiplied by resistance
  • Voltage equals resistance divided by current
  • Voltage equals current divided by resistance

Ohm's Law ( I = E / R ) becomes E = R*I when solving for E. Voltage is resistance times current. Volts = ohms * amperes.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What is the resistance of a circuit that draws 0.25 amperes from a 12-volt source?

  • 12 ohms
  • 3 ohms
  • 0.25 ohms
  • Correct Answer
    48 ohms

Ohm's Law ( I = E / R ) becomes R = E / I when solving for R. Resistance is voltage divided by current. Ohms = volts / amperes. 12 volts / 0.25 amperes = 48 ohms.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What value of resistance is required to drop 9 volts with a current of 10 milliamperes?

  • 90 ohms
  • 9000 ohms
  • Correct Answer
    900 ohms
  • 9 ohms

Ohm's Law ( I = E / R ) becomes R = E / I when solving for R. Resistance is voltage divided by current. Ohms = volts / amperes. 100 volts / 0.0008 amperes = 125 000 ohms = 125 kilohms. [ Note that volts divided by milliamperes is kilohms ]

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

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If the current flowing through a 50-ohm resistor is 0.44 amperes, what voltage would you measure across the resistor?

  • Correct Answer
    22 volts
  • 222 volts
  • 0.22 volts
  • 2.2 volts

Ohm's Law ( I = E / R ) becomes E = R*I when solving for E. Voltage is resistance times current. Volts = ohms * amperes. 50 ohms * 0.44 amperes = 22 volts.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

A 30-ohm resistor is connected across a 6-volt battery. What current does it draw?

  • 2 amperes
  • 0.5 amperes
  • 0.005 amperes
  • Correct Answer
    0.2 amperes

Ohm's Law ( I = E / R ). Current is voltage divided by resistance. Amperes = volts / ohms. 6 volts / 30 ohms = 0.2 amperes.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What voltage is needed to supply a current of 200 milliamperes to operate a relay that has a resistance of 25 ohms?

  • 8 volts
  • 50 volts
  • 0.5 volts
  • Correct Answer
    5 volts

Ohm's Law ( I = E / R ) becomes E = R*I when solving for E. Voltage is resistance times current. Volts = ohms * amperes. 25 ohms * 0.200 amperes = 5 volts.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What formula calculates the resistance of a circuit when the voltage and current are known?

  • Correct Answer
    R = E / I
  • R = E x I
  • R = E squared / I
  • R = I / E

Ohm's Law ( I = E / R ) becomes R = E / I when solving for R. Resistance is voltage divided by current. Ohms = volts / amperes.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

What is the resistance of a circuit if it draws 300 milliamperes from a 3-volt battery?

  • Correct Answer
    10 ohms
  • 5 ohms
  • 3 ohms
  • 9 ohms

Ohm's Law ( I = E / R ) becomes R = E / I when solving for R. Resistance is voltage divided by current. Ohms = volts / amperes. 3 volts / 0.300 amperes = 10 ohms.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

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