Electronics Information Flashcards
In metals, increasing temperature typically _______ conductivity?
Ⓐ. Decreases
Ⓑ. Does nothing to
Ⓒ. Doubles
Ⓓ. Increases
Ⓐ. Decreases
Explanation:
As the temperature of a metal increases, its conductivity decreases.
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
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)
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.
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 ⌈➡️➡️➡️⌉ ⌈− − / − −⌉ 🔋 🌕 🔋 🌑 ⌊⬅️⬅️⬅️⌋ ⌊ − − − − ⌋
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.
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.
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.
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.
⊕ This is the circuit symbol for a _______.
Ⓐ. Lamp
Ⓑ. Transistor
Ⓒ. Rheostat
Ⓓ. Connected wires
Ⓓ. Connected wires
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.
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.
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.
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.
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.