**Ohm’s Law** states that the voltage across a resistor is equal to the current flowing through it multiplied by the resistance. The formula is **V = I * R**.
What does Kirchhoff’s Current Law (KCL) state?
A The sum of the currents in a closed loop equals zero
B The sum of the currents entering a junction equals the sum of the currents leaving the junction
C The total voltage in a series circuit is the sum of individual voltages
D The voltage across any two points in a circuit is constant
**Kirchhoff’s Current Law (KCL)** states that the sum of currents entering a junction is equal to the sum of currents leaving that junction, based on the conservation of charge.
What does Kirchhoff’s Voltage Law (KVL) state?
A The sum of currents entering a junction is equal to the sum leaving the junction
B The sum of the voltages in a closed loop equals zero
C The total resistance in a series circuit equals the sum of individual resistances
D The voltage drop across a component is constant in a parallel circuit
**Kirchhoff’s Voltage Law (KVL)** states that the sum of all voltages around a closed loop in a circuit must equal zero, based on the conservation of energy.
What is the characteristic of a series circuit?
A The voltage across all components is the same
B The total current is the same throughout the circuit
C The total current is divided among the components
D The total resistance decreases with more components
In a **series circuit**, the current is the same throughout all components, while the voltage divides among the components according to their resistances.
How do you calculate the total resistance in a parallel circuit?
A R_total = R1 + R2 + … + Rn
B 1/R_total = 1/R1 + 1/R2 + … + 1/Rn
C R_total = R1 * R2 * … * Rn
D R_total = (R1 + R2) / 2
In a **parallel circuit**, the total resistance is calculated by taking the reciprocal of the sum of the reciprocals of the individual resistances:
**1/R_total = 1/R1 + 1/R2 + … + 1/Rn**.
What happens to the impedance in a purely inductive AC circuit as the frequency increases?
A The impedance decreases
B The impedance increases
C The impedance stays constant
D The impedance becomes zero
In a **purely inductive AC circuit**, **inductive reactance (XL)** increases with frequency. The formula for **XL** is **XL = 2πfL**, where **f** is the frequency and **L** is the inductance.
What is the resonance condition in an RLC circuit?
A The impedance is maximized
B The inductive reactance equals the capacitive reactance
C The total current is minimized
D The voltage across the circuit is minimized
**Resonance** in an **RLC circuit** occurs when the **inductive reactance** (**XL**) equals the **capacitive reactance** (**XC**). This results in minimal total impedance and maximized current.
What is the **total power** in a resistive AC circuit?
A P = V * I * cos(θ)
B P = I² * R
C P = V² / R
D P = V * I
In a **resistive AC circuit**, the power dissipated is calculated as **P = I² * R**, where **I** is the current and **R** is the resistance.
What happens to the **impedance** in a purely capacitive AC circuit as the frequency increases?
A The impedance increases
B The impedance decreases
C The impedance stays the same
D The impedance becomes zero
In a **purely capacitive AC circuit**, the **capacitive reactance (XC)** decreases as the frequency increases because **XC = 1 / (2πfC)**.
What happens to the **total resistance** in a series circuit when additional resistors are added?
A The total resistance decreases
B The total resistance increases
C The total resistance stays the same
D The total current decreases
In a **series circuit**, adding resistors increases the total resistance because the resistances are added together.
What happens to the **voltage** in a **parallel circuit**?
A The voltage is divided among the components
B The voltage is the same across all components
C The voltage is zero across each component
D The voltage increases with the number of components
In a **parallel circuit**, the voltage across each component is the same as the supply voltage, regardless of the number of components.
What is **resonance** in an RLC circuit?
A The impedance is maximized
B The inductive reactance equals the capacitive reactance
C The total current is minimized
D The voltage is minimized
**Resonance** occurs when the **inductive reactance (XL)** equals the **capacitive reactance (XC)**, which results in maximum current flow and minimum impedance.
What happens to the **total current** in a parallel circuit when more resistors are added?
A The current decreases
B The current increases
C The current remains the same
D The current becomes zero
In a **parallel circuit**, adding more resistors provides additional paths for the current to flow, which increases the total current supplied by the source.
What is **impedance** in an AC circuit?
A The total resistance only
B The total resistance to current flow, including reactance
C The energy stored in the circuit
D The power consumed by the circuit
**Impedance** is the total opposition to current flow in an AC circuit, combining both **resistance (R)** and **reactance (X)**. It is measured in ohms (Ω).
What happens to the **voltage** in a series circuit if the total resistance increases?
A The voltage across each resistor remains the same
B The voltage across each resistor increases
C The total voltage decreases
D The current becomes zero
In a **series circuit**, when the total resistance increases, the voltage across each resistor increases proportionally according to **Ohm’s Law**, with **V = I * R**.
What happens in a purely resistive AC circuit if the frequency increases?
A The resistance increases
B The impedance stays the same
C The current increases
D The impedance decreases
In a **purely resistive AC circuit**, the **impedance** remains constant regardless of the frequency, since **impedance** is only dependent on **resistance** in such circuits.
What is the **phase difference** between current and voltage in a purely capacitive AC circuit?
A Current leads voltage by 90 degrees
B Voltage leads current by 90 degrees
C Voltage and current are in phase
D There is no phase difference
In a **purely capacitive AC circuit**, the **voltage leads the current by 90 degrees**, meaning the voltage reaches its peak one-quarter cycle before the current.
What is the unit of **inductance** in an AC circuit?
A Volt
B Ampere
C Henry
D Ohm
The unit of **inductance** is the **henry (H)**. Inductance measures the ability of an inductor to resist changes in current and is an important factor in determining the impedance of inductive components.
What is the **total power** in an AC circuit with a **power factor of 1**?
A The total power is less than the apparent power
B The total power is equal to the real power
C The total power is zero
D The total power is equal to the apparent power
When the **power factor** is **1**, all of the **apparent power** is converted into **real power**, meaning the circuit is operating at maximum efficiency with no reactive power losses.
What does **energy transfer** in an electrical circuit refer to?
A The movement of energy from the source to the load
B The movement of electrical energy from the source to the load
C The dissipation of power as heat
D The conversion of electrical energy to light
**Energy transfer** refers to the movement of electrical energy from the **source** (like a power supply) to the **load** (such as a light bulb or motor), where it is consumed or stored.