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Flashcards in Electronics Information Deck (25)
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1

In metals, increasing temperature typically _______ conductivity?

Ⓐ. Decreases
Ⓑ. Does nothing to
Ⓒ. Doubles
Ⓓ. Increases

Ⓐ. Decreases

Explanation:
As the temperature of a metal increases, its conductivity decreases.

2

Use Ohm's Law to calculate the value of current in a circuit if voltage = 10.00 volts and resistance = 20.00 ohms.

Ⓐ. 0.50 amps
Ⓑ. 0.25 amps
Ⓒ. 1.00 amps
Ⓓ. 200.00 amps

Ⓐ. 0.50 amps

Explanation:
10.00 volts / 20.00 Ohms = 0.50 amps

3

Which of the following is the correct formula for Ohm's Law?

Ⓐ. V = √IR
Ⓑ. V = I/R
Ⓒ. V = I x R
Ⓓ. V = I²R

Ⓒ. V = IxR

Explanation:
Current (I) is measured in Amperes (A)
Voltage (V) is measured in Volts (V)
Resistance (R) is measured in Ohms (Ω)

Ohm's law is...
I = V ÷ R (A = V ÷ Ω)
V = I × R (V = A × Ω)
R = V ÷ I (Ω = V ÷ A)

4

Currents in an electric circuit creates heat because:

Ⓐ. The wire in the circuit burns when current passes through
Ⓑ. Heat is created when the current overcomes resistance in the wire
Ⓒ. Voltage is naturally hot
Ⓓ. Heat is created when the current overcomes the voltage in the wire

Ⓑ. Heat is created when the current overcomes resistance in the wire

Explanation:
Temperature is measured by the amount of energy in a system. If there is no resistance, no energy is required for the current to pass through the wire. If there is resistance, the current must now generate energy, thus raising the temperature in the system, in order to overcome the resistance and pass through the wire.

5

Electricity cannot flow...

Ⓐ. Through an open circuit
Ⓑ. Through a circuit with resistance
Ⓒ. Through a closed circuit
Ⓓ. Through a circuit under load

Ⓐ. Through an open circuit

Explanation:
Closed circuit Open circuit
⌈➡️➡️➡️⌉ ⌈− − / − −⌉
🔋 🌕 🔋 🌑
⌊⬅️⬅️⬅️⌋ ⌊ − − − − ⌋

6

What subatomic particle is responsible for electricity?

Ⓐ. Neutron
Ⓑ. Ampere
Ⓒ. Electron
Ⓓ. Quark

Ⓒ. Electron

Explanation:
The electron is a subatomic particle [symbols: (e-) or (β-)] with a negative elementary electric charge.

7

A diode to an electric circuit is like a ______ to a city.

Ⓐ. Parking lot
Ⓑ. One-way street
Ⓒ. City Hall
Ⓓ. Traffic light

Ⓑ. One-way street

Explanation:
A diode is an electrical device allowing current to move through it in one direction with far greater ease than in the other.

8

Silver is a better conductor of electricity, but copper is used more often in electrical circuits. Why?

Ⓐ. Copper has a higher melting point than silver
Ⓑ. Copper is less likely to be stolen than silver
Ⓒ. Copper is cheaper than silver
Ⓓ. Copper is stronger than silver

Ⓒ. Copper is cheaper than silver

Explanation:
Copper cost less than silver.

9

Which of the following statements about electrical resistance is true?

Ⓐ. The less resistive the conductor is the slower electron flow will be
Ⓑ. The less resistive the conductor is the faster electron flow will be
Ⓒ. Electrically conductive materials have no resistive properties
Ⓓ. The more resistive the conductor is the faster electron flow will be

Ⓑ. The less resistive the conductor is the faster electron flow will be

Explanation:
The speed of electrons flow is directly related to how much resistance there is. If there is a large amount of resistance then the electron flow will be slow. Is there is a small amount of resistance than the electron flow will be fast.

10

⊕ This is the circuit symbol for a _______.

Ⓐ. Lamp
Ⓑ. Transistor
Ⓒ. Rheostat
Ⓓ. Connected wires

Ⓓ. Connected wires

11

An amplifier is most similar in function to which of the following

Ⓐ. A step-up transformer
Ⓑ. An inverter
Ⓒ. A capacitor
Ⓓ. A step-down transformer

Ⓐ. A step-up transformer

Explanation:
An amplifier is a device that takes a small input signal and creates a larger output signal. This makes it most similar to a step up transformer which takes a smaller input voltage and creates a larger output voltage.

12

Regarding magnets, what is a measure of the quantity of magnetism?

Ⓐ. Reluctance
Ⓑ. Retentivity
Ⓒ. Permeability
Ⓓ. Magnetic flux

Ⓓ. Magnetic flux

Explanation:
Magnetic flux is the quantity of magnetism expressed by total number of magnetic lines of force.

13

If they transformer has a primary winding with 200 turns and a secondary winding with 20 turns, what is the transformation ratio?

Ⓐ. 10:10
Ⓑ. 10:1
Ⓒ. 10:10
Ⓓ. 1:10

Ⓑ. 10:1

Explanation:
The transformation ratio for a transformer compares the number of turns in the primary winding to the number of turns in the secondary winding. In this case, that ratio is 200:20 which reduces to 10:1.

14

Which of the following is not a purpose of a resistor in an electrical circuit?

Ⓐ. Moderate the heat in the circuit
Ⓑ. Limit the current in the circuit
Ⓒ. Randomize the current in the circuit
Ⓓ. Control the voltage in the circuit

Ⓒ. Randomize the current in the circuit

Explanation:
Resistors can be in a wide variety of values to control the voltage in the circuit, limit the current, or moderate the heat produced by the components in the circuit.

15

You would measure the amount of voltage between two points in the circuit with a(n):

Ⓐ. Capacitor
Ⓑ. Thermometer
Ⓒ. Ohm reader
Ⓓ. Voltmeter

Ⓓ. Voltmeter

Explanation:
A voltmeter is used to measure the voltage between two points in a circuit.

16

♒️ This is the circuit symbol for a _______.

Ⓐ. Ground
Ⓑ. Fuse
Ⓒ. Unconnected wires
Ⓓ. Resistor

Ⓓ. Resistor

17

Which of the following is not a common type of battery?

Ⓐ. Power-cycle
Ⓑ. Wet cell
Ⓒ. Deep-cycle
Ⓓ. Dry cell

Ⓐ. Power-cycle

Explanation:
The three most common types of batteries are dry cell (Used in small devices like TV remotes), wet cell (used for cars), and deep-cycle (storage batteries used primarily for backup and emergency power).

18

→⊢ This is the circuit symbol for a ______.

Ⓐ. Transistor
Ⓑ. Capacitor
Ⓒ. Diode
Ⓓ. Potentiometer

Ⓒ. Diode

19

How would you connect eight [6V5A] batteries to achieve a combined power output of 48V 5A?

Ⓐ. Parallel-series
Ⓑ. Series
Ⓒ. Parallel
Ⓓ. Series-parallel

Ⓑ. Series

Explanation:
Connecting the eighth batteries in series multiplies there voltage while keeping their current the same yielding a 48V5A combination.

20

Ohm's law can be written in each of the following ways except:

Ⓐ. I = R/V
Ⓑ. R = V/I
Ⓒ. I = V/R
Ⓓ. V = IR

Ⓐ. I = R/V

Explanation:
Ohm's law can be written in terms of current (I = V/R), in terms of voltage (V = IR), and in terms of resistance (R = V/I).

21

Which of the following is not a terminal on a transistor?

Ⓐ. Base
Ⓑ. Output
Ⓒ. Collector
Ⓓ. Emitter

Ⓑ. Output

Explanation:
A transistor has at least three terminals for connection to an external circuit. They are the: base, emitter, and collector terminals.

22

You would measure the amount of current through a circuit with a(n):

Ⓐ. Thermometer
Ⓑ. Voltmeter
Ⓒ. Battery
Ⓓ. Ammeter

Ⓓ. Ammeter

Explanation:
An ammeter is used to measure the electric current in a circuit.

23

What is the primary difference between a rectifier and an inverter?

Ⓐ. A rectifier converts a DC input to AC while an inverter converts an AC input to DC.
Ⓑ. A rectifier multiplies DC current while an inverter multiplies AC current
Ⓒ. A rectifier converts an AC input to DC while an inverter converts a DC input to AC
Ⓓ. A rectifier multiplies AC power while an inverter multiplies DC power

Ⓒ. A rectifier converts an AC input to DC while an inverter converts a DC input to AC

Explanation:
A rectifier is used to convert an AC input to DC and an inverter is used to convert a DC input to AC.

24

Capacitors connected in series produce ______ capacitance compared to capacitors connected in parallel.

Ⓐ. Double
Ⓑ. Less
Ⓒ. The same
Ⓓ. More

Ⓑ. Less

Explanation:
Capacitors connected in series produce less capacitance than capacitors connected in parallel.

25

In a household electrical wiring, which color of insulation indicates the 'hot' wire?

Ⓐ. Black
Ⓑ. Copper
Ⓒ. White
Ⓓ. Green

Ⓐ. Black

Explanation:
In the NM cable used for wiring homes, each cable has three wires inside a sheath with each wire covered in a different color of insulation to indicate its type. The wire with the black insulation is the 'hot' wire, white is the neutral wire, and the ground wire is either covered in green insulation or left bare.