NCCER Introduction to Electrical Circuits (26103-23) Practice Test

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• Which of the following best describes a short circuit?
• Which formula correctly represents power in terms of voltage and current?
• In a parallel circuit, how does the voltage across each branch compare to the source voltage?
• In a DC circuit with a capacitor, as time passes after applying voltage, the charging current does what?
• Which statement is true about current?
• A flow of one coulomb per second past a point in a circuit describes which quantity?
• Which statement is NOT a correct expression for power in watts?
• Kirchhoff's voltage law (KVL) states what about voltages in a closed loop?
• Copper is classified as a(n)?
• What does the rating on a fuse indicate?
• An electrical device that operates on the principle of magnetism is a ______.
• What is the power dissipated in the 3 Ω resistor when connected to a 9 V source?
• The power in a 120V circuit with a current of 5A is
• Which unit is used to measure resistance?
• Joules are units of
• What is the difference between a fuse and a circuit breaker in terms of resetting after an event?
• In the Brown-Black-Red-Gold example, which color in the third position represents the multiplier?
• An insulator typically has valence electrons in the valence shell of at least how many?
• If the voltage is 240V and the resistance is 60 ohms, the circuit current is ____ A.
• Which statement describes a conductor?
• In the formula I = E/R, what does E represent?
• An electrical device that operates by chemically creating a potential difference between two points is a ___.
• If current is 3 A and voltage is 240 V, power is
• What is a schematic diagram?
• If the first two digits are 1 and 0 and the third band multiplier is 100, what is the resistance value?
• What is the basic unit of electric current?
• Which subatomic particle carries a negative charge?
• Resistance is measured using a(n) ______.
• Doubling the source voltage in the same series circuit with the same resistors, what happens to the current?
• How do you calculate total resistance in a parallel circuit?
• A circuit contains at minimum
• If a device consumes 5 W for 2 hours, how much energy is used in watt-hours?
• Calculate the power in a circuit where the source is 240 V and the current is 10 A.
• If voltage is 120V and resistance is 24 ohms, current is
• One ampere is equal to how many coulombs per second?
• A device that uses magnetic fields to produce motion is a ______.
• What is the formula for resistance using voltage and current?
• What is the function of a diode in a circuit?
• A type of subatomic particle with a positive charge is a(n)?
• In a simple series circuit with a 12 V source and three resistors in series (R1 = 4 Ω, R2 = 6 Ω, R3 = 10 Ω), what is the total resistance?
• What instrument measures resistance?
• What is the primary safety purpose of grounding in electrical systems?
• Kirchhoff's current law (KCL) states what about currents at a junction?
• If the circuit voltage remains the same and resistance is halved, what happens to power according to P = V^2 / R?
• What is the typical unit for electrical energy?
• Which statement correctly describes energy usage units in homes?
• Voltage is the potential difference between two points.
• How does an ohm meter determine resistance?
• If 6.25 x 10^18 electrons pass in 2 seconds, what is the current?
• In a 4-band resistor color code, what does the third band represent?
• In a circuit with a 10 Ω resistor and a current of 2 A, what is the voltage across the resistor?
• To calculate current flowing in a circuit, you must
• Which instrument is used to measure voltage?
• Another term used for voltage
• Where should a voltmeter be connected to measure the voltage across a component?
• If V = 9 V and I = 3 A, what is the resistance R?
• Magnetic lines of force are also referred to as ___.
• An electron repels a(n) ______.
• In a parallel combination of resistors, removing one branch causes the equivalent resistance to do what?
• Which quantity is equal to the flow of electric charge per unit time?
• In a four-band resistor color code, how many significant digits are provided by the first two bands?
• Which of the following is NOT a unit of power?
• In a parallel circuit, current distribution among branches is ...?
• In the 24 V parallel circuit with R3 = 4 Ω, what is the current through R3?
• Which expression gives electrical power in terms of voltage and current?
• In the series circuit above, what is the voltage drop across R2?
• Electricity is the flow of ______.
• Which of the following is the unit of electric charge?
• In the resistor color code example Brown-Black-Red-Gold, what does the Gold band indicate?
• If the resistance quadruples while the voltage remains constant, what happens to the current?
• Which category lies between insulators and conductors?
• Which description best defines an electrical load in a circuit?
• In a parallel combination of resistors, if one branch is removed, what happens to the equivalent resistance?
• In a DC steady-state for an RC circuit, what does the capacitor do?
• A resistor with a gold band in the fourth position has a tolerance of ___.
• Which unit equals 1,000 watt-hours of energy?
• Magnetic lines of force are also referred to as flux lines. Which term describes this concept?
• In the same series circuit, what is the current through each resistor?
• Which material is a common conductor?
• What is the circuit current if the voltage source is 120V and the resistance is 10 ohms?
• In AC circuits, what does RMS (root-mean-square) represent?
• In a parallel circuit with a 24 V source and three resistors in parallel: R1 = 8 Ω, R2 = 12 Ω, R3 = 4 Ω. What is the total current drawn from the source?
• Which material is considered an electrical insulator?
• Which of the following is a non-SI unit of power commonly used to rate electrical equipment?
• Which material is a poor conductor?
• Which quantity is measured in amperes?
• Objects charged with the same type of charge will push each other away. This is referred to as:
• In a series circuit, how does the voltage drop distribute across resistors?
• Which factor does not affect resistance in the relation R = ρL/A?
• What is the purpose of a breaker box?
• Which symbol is commonly used to denote electrical power?
• What safety practice requires you to disconnect power and verify zero energy before work?
• Which component stores energy electrostatically in a circuit?
• The most common method of producing electricity is through the use of _____.
• The smallest unit of an element that retains its chemical properties is called an ______.
• Two 5-ohm resistors in parallel have an equivalent resistance of?
• In the series circuit, what is the voltage across R1 if the current is 0.6 A and R1 = 4 Ω?
• If the resistance of a circuit is 20 ohms and the current is 15 amps, the power in watts is ___.
• Which rule expresses that the sum of voltages around a closed loop equals zero?
• Current flowing through a conductor coiled around an iron bar produces a(n)?
• Valence electrons reside in which shell?
• Which statement accurately describes current (I), voltage (V), and resistance (R)?
• Which statement is true about the relationship between kilowatt-hours and joules?
• Which instrument is used to measure resistance?
• What is an ohm meter used for?
• In an electromagnet, what happens if you increase the number of turns on the coil while keeping the current the same?
• Which device measures electrical resistance?
• If 6.25 x 10^18 electrons pass a point in 2 seconds, what is the current?
• What is the formula for electrical power when expressed in terms of voltage and resistance?
• How can power factor be improved in AC circuits?
• An atom with seven valence electrons is most likely a(n)?
• Voltage is defined as the difference of potential.
• If a current of 3 amperes flows, how much charge passes each second?
• What is the unit of electrical resistance?
• What is the SI unit of power?
• What is the difference between DC and AC voltages?
• Which is an example of a semiconductor?
• An insulator is normally an atom with ___ electrons in the valence shell.
• Which device stores energy electrostatically in a circuit?
• If a circuit has 12 V across a 4 Ω resistor, what is the power dissipated?
• What is the term for an amount of electric charge equal to 6.25 x 10^18 electrons?
• Which of the following does not affect wire resistance?
• The total resistance in a 120 V circuit in series with three 10 Ω resistors is ____.
• A conductor is normally made of atoms with ___ valence electrons.
• What is the power dissipated by the 10 Ω resistor carrying 2 A?
• If 6.25 x 10^18 electrons pass a point in one second, the current is approximately?
• A semiconductor is normally an atom with ___ electrons in the valence shell.
• Opposition to current flow is known as
• If circuit has 20 amps and 240 volts, resistance is?
• In a typical US residential circuit, which color is hot and which is neutral?
• What is the unit for electrical resistance?
• Which statement best describes a coulomb?
• How many amperes are in 1 milliampere (mA)?
• How do you identify a series versus parallel circuit in a schematic?
• What is power factor in AC circuits?
• In a circuit with a 9 V battery and a 3 Ω resistor, what is the current?
• Which statement is true regarding the use of a clamp-on ammeter?
• Which of the following is an SI unit of power?
• If a load operates at 100 V and draws 3 A, what is the power in watts?
• What is the unit commonly used to measure electrical energy consumption by utilities?
• What safety device protects circuits by interrupting excessive current?
• Two 5-ohm resistors in series total resistance?
• Which expression correctly represents power when using current and resistance as P = I^2 × R?
• What is the SI unit of electric current?
• Which instrument is used to measure current?
• Coulombs are a measure of ____.
• Which statement describes grounding as a safety feature?
• 1000 mils equals how many inches?
• Objects charged with different type of charges will draw toward each other. This is referred to as:
• Which expression gives electrical power in terms of current and resistance?
• Which statement correctly expresses power using resistance only?
• What is Ohm's law equation?
• Current is measured in units called
• If the current is 5 A in a circuit with a resistance of 2 ohms, the power dissipated is ____ watts.
• The voltage commonly supplied to a residence by the local utility is
• A resistor has no fourth band; tolerance is 20%.
• A 1500 W device runs for 2 hours. How many watt-hours of energy does it consume?
• In the resistor color code Brown-Black-Red-Gold, what is the resulting resistance value and tolerance?
• Which statement describes the difference between a conductor and an insulator regarding electron movement?
• How does an inductor respond to a sudden change in current?
• Which component is most commonly considered a load in household circuits?
• Which component is used to step up voltage for transmission?
• The three principal parts of an atom are
• A proton repels which of the following particles?
• Which equation defines current in terms of charge and time?
• Which statement correctly describes a parallel circuit?
• In a parallel circuit, the voltage drop across each load is the same.
• Which of the following best describes an open circuit?
• Find the applied voltage when the current is 30 A and the resistance is 4 Ω.
• Which material is considered a good semiconductor?
• In a series circuit, adding resistors increases total resistance.
• What is the smallest unit of an element that cannot be chemically subdivided?
• Which statement describes an insulator?
• The charge of a single electron is approximately?
• Which component is used to open or close a circuit and can be normally open or normally closed?
• If a device uses 2 A at 120 V, what is its power in watts?
• Which PPE hazard protections does proper PPE provide in electrical work?