A The relationship between current, voltage, and resistance
B Voltage equals current times resistance
C Resistance equals voltage times current
D Power equals voltage times current
**Ohm’s Law** states that the voltage across a resistor is equal to the current flowing through it multiplied by the resistance, represented as **V = I * R**.
What does **Kirchhoff’s Current Law (KCL)** apply to?
A Voltage drop across a resistor
B The sum of currents entering and leaving a junction
C The energy stored in capacitors
D The total resistance in a circuit
**KCL** states that the total current entering a junction is equal to the total current leaving the junction, based on the conservation of electric charge.
What does **Kirchhoff’s Voltage Law (KVL)** state?
A The sum of currents entering a junction is equal to the sum leaving
B The sum of the voltages in a closed loop equals zero
C The voltage across resistors in series is the same
D The total voltage is divided equally among resistors in series
**KVL** states that the sum of all voltages around a closed loop must equal zero, reflecting the conservation of energy in the circuit.
What is the total current in a **series circuit**?
A The total current is divided among all components
B The total current is the same throughout the circuit
C The total current is equal to the sum of individual currents
D The current decreases with each component added
In a **series circuit**, the current is the same through all components, but the voltage is divided according to each component’s resistance.
What happens to the total **resistance** in a **parallel circuit** when more resistors are added?
A The total resistance increases
B The total resistance decreases
C The total resistance stays the same
D The current decreases
In a **parallel circuit**, adding more resistors provides additional paths for current, which reduces the total resistance of the circuit.
What is the **impedance** in an AC circuit?
A The total current in the circuit
B The opposition to the flow of current, including both resistance and reactance
C The total voltage drop across components
D The resistance of inductive components
**Impedance** is the total opposition to current flow in an AC circuit, which combines **resistance (R)** and **reactance (X)** from both inductive and capacitive elements.
In a **purely capacitive AC circuit**, what happens to the impedance as the frequency increases?
A The impedance decreases
B The impedance increases
C The impedance remains constant
D The impedance becomes infinite
In a **purely capacitive AC circuit**, the **capacitive reactance (XC)** decreases as the frequency increases. This is because **XC = 1 / (2πfC)**, where **f** is frequency and **C** is capacitance.
What happens to the **total current** in a **series circuit** when more resistors are added?
A The current increases
B The current decreases
C The current remains the same
D The current becomes zero
In a **series circuit**, adding more resistors increases the total resistance, causing the total current to decrease according to **Ohm’s Law** (**I = V / R**).
What is the **resonance** frequency in an RLC circuit?
A The frequency where inductive and capacitive reactance cancel each other out
B The frequency at which the impedance is minimized
C The frequency where the current is minimized
D The frequency where the voltage drop across components is maximized
**Resonance** occurs when the **inductive reactance** and **capacitive reactance** in an RLC circuit cancel each other out, minimizing impedance and allowing maximum current to flow.
What happens to the **current** in a circuit with a **high power factor**?
A The current decreases
B The current increases
C The current remains constant
D The current becomes zero
A **high power factor** means the current and voltage are in phase, and there is less reactive power in the system. As a result, the current required to deliver the same amount of real power is reduced.
What happens when a **capacitor** is added to a circuit in **series**?
A The current increases significantly
B The capacitor blocks DC but allows AC to pass
C The capacitor stores all the energy
D The capacitor increases the voltage drop
A **capacitor** in **series** blocks **DC** once it is fully charged, but it allows **AC** to pass through, filtering or smoothing the signal.
How do **filters** work in an electrical circuit?
A They pass certain frequencies while blocking others
B They amplify all frequencies
C They store excess energy
D They increase the current in the circuit
**Filters** are used to allow specific frequencies to pass through while blocking others, commonly used in signal processing and communication systems.
What happens when **more resistors** are added to a **series circuit**?
A The total current increases
B The total resistance increases
C The total voltage increases
D The total current remains the same
In a **series circuit**, adding more resistors increases the **total resistance**, which causes the total current to decrease, according to **Ohm’s Law** (**I = V / R**).
What is the result of **adding more capacitors** in **parallel** with a circuit?
A The total capacitance decreases
B The total capacitance increases
C The total capacitance remains constant
D The voltage across each capacitor increases
In a **parallel circuit**, adding more capacitors increases the **total capacitance**, as the total capacitance is the sum of individual capacitances: **C_total = C1 + C2 + …**.
What is the effect of **increasing the frequency** on the **impedance** of a purely inductive circuit?
A The impedance decreases
B The impedance increases
C The impedance remains constant
D The impedance becomes zero
In a **purely inductive circuit**, **inductive reactance** increases with frequency, so the **impedance (Z = XL)** increases as frequency increases.
What is the total power in a circuit with a **high power factor**?
A The total power is more efficiently used
B The current increases significantly
C The voltage drop decreases to zero
D The voltage increases significantly
A **high power factor** means that the current and voltage are in phase, and more of the supplied power is converted into useful work, improving overall efficiency.
What is **resonance** in an RLC circuit?
A The voltage across the components is minimized
B The inductive and capacitive reactances cancel each other out
C The current is minimized
D The impedance reaches its maximum value
**Resonance** occurs when the **inductive reactance (XL)** equals the **capacitive reactance (XC)** in an RLC circuit, canceling each other out, resulting in minimum impedance and maximum current.
What is the role of a **diode** in a circuit?
A To allow current to flow in only one direction
B To store energy
C To amplify signals
D To increase the current in the circuit
A **diode** allows current to flow only in one direction, making it essential for converting AC to DC in rectification circuits.
What is **transient analysis** used for in an electrical circuit?
A To study the steady-state behavior of the circuit
B To analyze the circuit’s behavior immediately after a sudden change in conditions
C To calculate the total power consumed
D To find the current in the circuit at steady state
**Transient analysis** is used to study the circuit’s behavior immediately after a sudden change in voltage, current, or switch operation. It is critical for understanding how the circuit responds over time before it reaches steady state.
What is the **total power** in an AC circuit with a power factor of 1?
A All of the supplied power is used for useful work
B Some of the power is lost as reactive power
C The circuit is inefficient
D Only reactive power is used
A **power factor** of 1 means that all of the supplied power is used for useful work, with no reactive power in the system. This is the most efficient condition for power usage.