DC Circuit Question & Answers June 14, 2023 By Wat Electrical This article lists 75 DC Circuit MCQs for engineering students. All the DC Circuit Questions & Answers below include a hint and a link to the relevant topic wherever possible. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of the DC Circuit. In electrical engineering, a DC (direct current) circuit refers to a circuit where the current flows in one direction without changing its polarity over time. In a DC circuit, the voltage sources provide a constant voltage, and the components, such as resistors, capacitors, and inductors, behave in a steady state. In a DC circuit, the behavior of the components is governed by Ohm's Law, which states that the current flowing through a resistor is directly proportional to the voltage across it and inversely proportional to its resistance. By applying Kirchhoff's laws, Ohm's Law, and understanding the behavior of components like resistors, capacitors, and inductors, engineers can analyze and design various DC circuits for a wide range of applications. 1). What is the formula to calculate the total resistance in a series circuit? R = R1 + R2 + R3 1/R = 1/R1 + 1/R2 + 1/R3 R = R1 * R2 * R3 R = (R1 + R2 + R3) / 3 Hint 2). What is the formula to calculate the total resistance in a parallel circuit? R = R1 + R2 + R3 1/R = 1/R1 + 1/R2 + 1/R3 R = R1 * R2 * R3 R = (R1 + R2 + R3) / 3 Hint 3). What is the formula to calculate the current flowing through a resistor in a series circuit? I = V / R I = R / V V = I * R R = I / V Hint 4). What is the formula to calculate the voltage across a resistor in a series circuit? V = I / R V = R / I I = V * R R = V / I Hint 5). Which of the following statements is true for a parallel circuit? The total resistance is always greater than the individual resistances The total current is always greater than the individual currents The total voltage is always greater than the individual voltages The total resistance is always less than the individual resistances Hint 6). Which of the following statements is true for a series circuit? The total resistance is always greater than the individual resistances The total current is always greater than the individual currents The total voltage is always greater than the individual voltages The total resistance is always less than the individual resistances Hint 7). What is the formula to calculate power dissipated by a resistor? P = V * I P = V / I P = I / V P = R * I^2 Hint 8). Who is credited with discovering the concept of the electric circuit? Thomas Edison Nikola Tesla Michael Faraday Alessandro Volta Hint 9). The first practical DC power distribution system was developed by _____________________? Thomas Edison George Westinghouse Benjamin Franklin Alexander Graham Bell Hint 10). The unit of electric current, the ampere (A), is named after ___________________? James Watt Alessandro Volta Andre-Marie Ampere Albert Einstein Hint 11). Which of the following laws describes the relationship between voltage, current, and resistance in a DC circuit? Ohm's Law Coulomb's Law Faraday's Law Newton's Law Hint 12). The first practical electric battery, known as the voltaic pile, was invented by ____________________? Michael Faraday Alessandro Volta Benjamin Franklin Thomas Edison Hint 13). The DC distribution system used by Thomas Edison was known as the _______________________? Alternating Current (AC) system Direct Current (DC) system Three-phase system Polyphase system Hint 14). Who invented the first practical electric generator? Michael Faraday Thomas Edison Nikola Tesla Charles Francis Brush Hint 15). The first long-distance transmission of DC power was accomplished by ________________________? Thomas Edison George Westinghouse Nikola Tesla Samuel Morse Hint 16). In a series DC circuit, which statement is true? The total resistance is equal to the sum of individual resistances The total voltage is divided equally across each resistor The total current is equal to the sum of individual currents The total power is equal to the product of individual powers Hint 17). In a parallel DC circuit, which statement is true? The total resistance is equal to the sum of individual resistances The total voltage is divided equally across each resistor The total current is equal to the sum of individual currents The total power is equal to the product of individual powers Hint 18). What happens to the total resistance when resistors are connected in parallel? It increases It decreases It remains the same It cannot be determined Hint 19). What happens to the total resistance when resistors are connected in series? It increases It decreases It remains the same It cannot be determined Hint 20). In a series-parallel DC circuit, which statement is true? The total resistance is equal to the sum of individual resistances The total voltage is divided equally across each resistor The total current is equal to the sum of individual currents The total power is equal to the product of individual power Hint 21). In a DC circuit, which component maintains a constant voltage across it? Resistor Capacitor Inductor Battery Hint 22). What is the unit of electric current? Volt Ohm Ampere Watt Hint 23). According to Ohm’s Law, the current flowing through a conductor is directly proportional to ______________________? Voltage Resistance Power Capacitance Hint 24). Which of the following materials is a good conductor of electricity? Wood Rubber Copper Glass Hint 25). If a resistor is connected in series with an ammeter, how will it affect the measured current? Increase the measured current Decrease the measured current Have no effect on the measured current Cause the ammeter to malfunction Hint DC Circuit MCQ for Quiz 26). Which of the following statements is true about a series circuit? The total resistance is equal to the sum of individual resistances The total current is equal to the sum of individual currents The voltage across each component is the same All of the above Hint 27). What happens to the total resistance of a parallel circuit as more resistors are added? Increases Decreases Stays the same Cannot be determined Hint 28). If a short circuit occurs in a circuit, what happens to the current? Increases to a very high value Decreases to zero Stays the same Becomes alternating current Hint 29). What is the formula for calculating power in a DC circuit? P = IV P = V^2/R P = I^2R All of the above Hint 30). Which component is commonly used to store electrical energy in a DC circuit? Resistor Capacitor Inductor Diode Hint Read more about Resistors 31). Kirchhoff’s first law is also known as ____________________? Ohm’s Law Faraday’s Law Ampere’s Law Conservation of Charge Hint 32). What is the purpose of a diode in a DC circuit? To regulate voltage To store electrical energy To rectify AC to DC To change the direction of current flow Hint 33). Which of the following is a passive component in a DC circuit? Battery Resistor Transistor Generator Hint 34). What is the unit of electrical resistance? Ampere Volt Ohm Watt Hint 35). Which of the following statements is true about a series circuit? The total resistance is equal to the sum of individual resistances The total current is equal to the sum of individual currents The voltage across each component is the same All of the above Hint 36). Which of the following statements is true about a parallel circuit? The total resistance is equal to the sum of individual resistances The total current is equal to the sum of individual currents The voltage across each component is the same All of the above Hint 37). Which type of circuit is commonly used in household electrical wiring? Series circuit Parallel circuit Combination circuit It depends on the specific application Hint 38). Which type of circuit is used in Christmas lights where one bulb failure does not affect the others? Series circuit Parallel circuit Combination circuit It depends on the specific design Hint 39). Which type of circuit is used in flashlights where multiple batteries are connected in a row? Series circuit Parallel circuit Combination circuit It depends on the specific design Hint 40). Which type of circuit configuration is used to calculate the equivalent resistance? Series circuit Parallel circuit Combination circuit All of the above Hint 41). Which type of circuit configuration is used to calculate the total current? Series circuit Parallel circuit Combination circuit All of the above Hint 42). Which type of circuit configuration is used to calculate the total voltage? Series circuit Parallel circuit Combination circuit All of the above Hint 43). Kirchhoff’s second law is also known as ___________________? Ohm’s Law Faraday’s Law Ampere’s Law Voltage Law Hint 44). Kirchhoff's laws provide a systematic method for ____________________? Calculating the resistance of a circuit Calculating the voltage of a circuit Analyzing and solving complex electrical circuits Determining the capacitance of a circuit Hint 45). Kirchhoff’s second rule is also known as __________________? Ohm’s Law Faraday’s Law Ampere’s Law Loop Rule Hint 46). According to Kirchhoff’s first rule, the algebraic sum of currents at a junction is _________________? Always zero Always positive Always negative Equal to the voltage Hint 47). According to Kirchhoff’s second rule, the algebraic sum of voltages around a closed loop is ____________________? Always zero Always positive Always negative Equal to the current Hint 48). Kirchhoff’s rules are useful for _____________________? Calculating current in a circuit Calculating voltage in a circuit Analyzing complex circuits All of the above Hint 49). In a series DC circuit _____________________? The voltage across each component is different The current remains the same through all components The total resistance is the sum of individual resistances All of the above Hint 50). In a parallel DC circuit _____________________? The voltage across each component is the same The current is divided among the branches The total resistance is the sum of individual resistances All of the above Hint DC Circuit MCQ for Exams 51). Which of the following is an application of DC circuits? Power transmission over long distances Audio amplification in speakers Charging batteries All of the above Hint 52). In a parallel circuit, the total resistance is ____________________________? Equal to the sum of individual resistances Less than the smallest individual resistance Greater than the largest individual resistance None of the above Hint 53). In a series circuit with a 9V battery and a resistor of 3 Ω, what is the power dissipated by the resistor? 3 W 6 W 9 W 27 W Hint 54). A circuit consists of three resistors connected in parallel. If the resistance values are R1 = 4 Ω, R2 = 6 Ω, and R3 = 8 Ω, what is the total resistance? 3 Ω 4 Ω 6 Ω 18 Ω Hint 55). In a series circuit, the total resistance is equal to _____________________? The sum of individual resistances The product of individual resistances The reciprocal of individual resistances The difference between individual resistances Hint 56). In a parallel circuit, the total resistance is equal to ________________________? The sum of individual resistances The product of individual resistances The reciprocal of individual resistances The difference between individual resistances Hint 57). If two resistors are connected in series, and one resistor has a resistance of 6 ohms while the other has a resistance of 4 ohms, what is the total resistance of the series combination? 2 ohms 4 ohms 6 ohms 10 ohms Hint 58). If two resistors are connected in parallel, and one resistor has a resistance of 8 ohms while the other has a resistance of 12 ohms, what is the total resistance of the parallel combination? 2.67 ohms 5 ohms 8 ohms 20 ohms Hint 59). In a series circuit, if a current of 2A flows through each resistor, and there are three resistors of equal value, what is the total current flowing in the circuit? 0.5A 2A 4A 6A Hint 60). In a series DC circuit, if one resistor fails or is removed, what happens to the current flowing through the other resistors? The current decreases in the other resistors The current increases in the other resistors The current remains the same in the other resistor The current becomes zero in the other resistors Hint 61). In a parallel DC circuit, if one resistor fails or is removed, what happens to the total current flowing through the circuit? The total current decreases The total current increases The total current remains the same The total current becomes zero Hint 62). In a series DC circuit, if the value of each resistor is doubled while keeping the voltage constant, what happens to the total resistance? The total resistance doubles The total resistance quadruples The total resistance remains the same The total resistance halves Hint 63). In a parallel DC circuit, if the value of each resistor is halved while keeping the voltage constant, what happens to the total resistance? The total resistance halves The total resistance doubles The total resistance remains the same The total resistance quadruples Hint 64). In a series circuit with three resistors, if one resistor fails (becomes open), what happens to the current flowing through the other resistors? The current decreases in the other resistors The current increases in the other resistors The current remains the same in the other resistors The current becomes zero in the other resistors Hint 65). In a parallel circuit with two resistors, if one resistor has a resistance of 10 ohms and the other resistor has a resistance of 20 ohms, what is the equivalent resistance of the circuit? 30 ohms 15 ohms 6.7 ohms 3.3 ohms Hint 66). If a series circuit has a total resistance of 50 ohms and a total current of 2 amperes, what is the voltage drop across each resistor? 100 volts 50 volts 25 volts 10 volts Hint 67). In a series circuit with three resistors of 10Ω, 15Ω, and 20Ω, what is the total resistance? 5Ω 10Ω 15Ω 45Ω Hint 68). In a parallel circuit with two resistors of 6Ω and 12Ω, what is the equivalent resistance? 3Ω 4Ω 6Ω 18Ω Hint 69). A 9V battery is connected to three resistors of 3Ω, 6Ω, and 9Ω in parallel. What is the total current drawn from the battery? 1A 3A 9A 8A Hint 70). A 12V battery is connected to two resistors of 4Ω and 6Ω in series. What is the voltage across the 6Ω resistor? 4V 6V 8V 12V Hint 71). A circuit has three resistors of 5Ω, 10Ω, and 15Ω connected in parallel. If the voltage across the 10Ω resistor is 8V, what is the total current in the circuit? 0.4A 0.8A 1.2A 2.4A Hint 72). In a series circuit with three resistors of values 2 Ω, 4 Ω, and 6 Ω, connected to a 12V battery, what is the total resistance? 12 Ω 8 Ω 2 Ω 1 Ω Hint 73). In a parallel circuit with two resistors of values 3 Ω and 6 Ω, connected to a 9V battery, what is the total resistance? 9 Ω 2 Ω 4 Ω 1 Ω Hint 74). In a series circuit with a 12V battery and a resistor of 4 Ω, what is the current flowing through the circuit? 12 A 6 A 4 A 3 A Hint 75). In a parallel circuit with a 6V battery and two resistors of values 3 Ω and 6 Ω, what is the current flowing through the 3 Ω resistor? 2 A 4 A 1 A 3 A Hint For More MCQs Magnetic Circuit Question & Answers Electric Circuit Question & Answers RLC Circuit Question & Answers Time's up