Watt’s Law Question & Answers May 30, 2023 By Wat Electrical This article lists 50 Watt's Law MCQs for engineering students. All the Watt's Law Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of Watt's Law. Watt's Law (unofficial term) states that the power (P) in an electrical circuit is equal to the product of the voltage (V) across a device and the current (I) flowing through it. Mathematically, it can be expressed as P = V * I. This formula indicates that power is directly proportional to both voltage and current. It implies that increasing either the voltage or the current will result in a corresponding increase in power, given that the other value remains constant. Power is the rate at which electrical energy is transferred or consumed in a circuit. It's important to note that this formula holds true for resistive circuits, where the voltage and current are in phase. Additional considerations such as power factor come into play in more complex circuits involving reactive components like capacitors and inductors. This law is mainly used for discovering or analyzing the voltage, ampere, resistance, & power. Watts can be utilized to decide the performance of the battery. 1). What is the formula for calculating power in an electrical circuit? P = V / I P = V * I P = I / V P = R * I Hint 2). A circuit has a voltage of 12 volts and a current of 2 amperes. What is the power consumed by the circuit? 10 W 14 W 24 W 6 W Hint 3). In an electrical circuit, the power dissipated is 60 watts, and the current flowing through it is 3 amperes. What is the voltage across the circuit? 18 V 120 V 20 V 180 V Hint 4). If the power consumed by a device is 500 W and the voltage across it is 100 V, what is the current flowing through the device? 2 A 500 A 100 A 5 A Hint 5). Who formulated Watts' Law? James Watt George Ohm Michael Faraday Thomas Edison Hint 6). When was Watts' Law formulated? 17th century 18th century 19th century 20th century Hint 7). What is the mathematical equation representing Watts' Law? V = IR P = IV R = VI I = VP Hint 8). Which of the following is not one of the variables in Watts' Law? Voltage (V) Current (I) Resistance (R) Power (P) Hint 9). What does Watts' Law describe? The relationship between voltage and current The relationship between power and resistance The relationship between voltage and resistance The relationship between power and current Hint 10). A circuit has a power of 200 watts and a voltage of 20 volts. What is the current flowing through the circuit? 10 amperes 2000 amperes 4000 amperes 0.1 amperes Hint Watt's Law MCQ for Exams 11). In a circuit, the current is 5 amperes, and the power dissipated is 1000 watts. What is the voltage across the circuit? 100 volts 500 volts 50 volts 200 volts Hint 12). A resistor has a power rating of 5 watts and a voltage across it of 10 volts. What is the maximum current that can flow through the resistor? 2 amperes 15 amperes 50 amperes 0.5 amperes Hint 13). A circuit has a resistance of 20 ohms and a current of 2 amperes. What is the power dissipated in the circuit? 10 watts 20 watts 40 watts 80 watts Hint 14). The power dissipated in a circuit is 500 watts, and the resistance is 50 ohms. What is the current flowing through the circuit? 5 amperes 10 amperes 25 amperes 100 amperes Hint 15). Watt's Law relates power, voltage, and current in an electrical circuit. Which of the following is a key feature of Watt's Law? Power is directly proportional to current. Power is directly proportional to voltage. Current is directly proportional to voltage. Hint 16). Which of the following statements accurately describes the relationship between voltage and current in Watt's Law? Voltage and current are directly proportional Voltage and current are inversely proportional. Voltage and current have no relationship The relationship between voltage and current depends on resistance Hint 17). In Watt's Law, if the power remains constant, what happens to the current when the voltage is doubled? The current is halved. The current is doubled. The current remains the same The current is quadrupled Hint 18). Which of the following is an advantage of Watt's Law in electrical calculations? It accurately predicts the resistance of a circuit. It allows for easy calculation of power in an electrical circuit. It determines the efficiency of an electrical device. It can be used to calculate the capacitance of a circuit. Hint 19). Watt's Law is applicable to which type(s) of electrical circuits? Only DC (Direct Current) circuits. Only AC (Alternating Current) circuits Both DC and AC circuits Neither DC nor AC circuits Hint 20). What advantage does Watt's Law offer in terms of circuit analysis? It simplifies complex circuit calculations It determines the energy consumption of a circuit It measures the magnetic field strength in a circuit It helps in determining the frequency of an electrical signal Hint 21). Which of the following principles is encompassed by Watt's Law? Conservation of energy Ohm's Law Kirchhoff's Law Faraday's Law Hint 22). Watt's Law is an application of which fundamental electrical principle? Ohm's Law Gauss's Law Ampere's Law Coulomb's Law Hint 23). What is the underlying principle behind Watt's Law? Conservation of charge Conservation of power Conservation of current Conservation of voltage Hint 24). Watt's Law is commonly used in which of the following applications? Electrical circuit analysis and design Wireless communication systems Chemical reactions Mechanical engineering Hint 25). Which of the following is an example of an application of Watt's Law? Calculating the heat transfer in a thermodynamic system Determining the resistance of a resistor Analyzing the motion of objects in a mechanical system Predicting the behavior of light in optical systems Hint 26). Watt's Law is utilized in which of the following electrical devices? Electric motors GPS navigation systems Chemical reactors Bicycle wheels Hint 27). Watt's Law is based on the principle of conservation of ________________? Power Voltage Energy Current Hint 28). In a circuit, the voltage is 10 volts, and the current is 2 amperes. What is the power consumed by the circuit? 5 W 10 W 15 W 20 W Hint 29). If a circuit has a resistance of 5 ohms and a current of 2 amperes, what is the voltage across the circuit? 2 V 5 V 7 V 10 V Hint 30). A device operates at a power of 60 W and is connected to a 120 V power source. What is the current flowing through the device? 0.5 A 2 A 5 A 10 A Hint 31). What happens to the power in an electrical circuit if both the voltage and current are doubled? The power becomes one-fourth The power becomes half The power remains the same The power is quadrupled. Hint 32). In terms of electrical quantities, Watt's Law is classified as a relationship between: Power and voltage. Current and resistance. Voltage and current Power and resistance Hint 33). Watt's Law falls under the category of which fundamental laws of physics? Laws of thermodynamics Laws of magnetism Laws of electricity and magnetism Laws of motion Hint 34). Which of the following scientists provided the theoretical foundation for Watt's Law? Georg Simon Ohm Michael Faraday André-Marie Ampère Charles-Augustin de Coulomb Hint Watt's Law MCQ for Interviews 35). Which formula is used to calculate current using Watt's Law? P = V * I V = I * R I = V / R P = I * R Hint 36). Which formula is used to calculate voltage using Watt's Law? P = V / I V = I * R I = V / R P = I * R Hint 37). Which law relates current, voltage, and resistance in an electrical circuit? Ohm's Law Watt's Law Faraday's Law Gauss's Law Hint 38). Which law states that the power in a circuit is equal to the product of voltage and current? Ohm's Law Watt's Law Ampere's Law Kirchhoff's Law Hint 39). What is the mathematical formula for Ohm's Law? V = I / R P = V × I R = V / I P = V + I + R Hint 40). Which law is used to calculate the power dissipated in a circuit? Ohm's Law Watt's Law Coulomb's Law Ohm's Law and Watt's Law both Hint 41).Which function or setting on a DMM should be selected to measure DC voltage? Resistance (Ω) Current (A) Voltage (V) Frequency (Hz) Hint 42). What is the typical range for measuring DC voltage on a DMM? 0-10 V 0-100 V 0-1000 V 0-10000 V Hint 43). When connecting a DMM to measure voltage, which terminals of the DMM should be used? Common (COM) and Voltage (V) Common (COM) and Current (A) Voltage (V) and Resistance (Ω) Voltage (V) and Frequency (Hz) Hint 44). If the DMM reads "OL" when measuring voltage, what does it indicate? Overload or open circuit Overvoltage or excessive voltage Out of range or incorrect measurement setting Operational error or malfunction Hint 45). What is the proper technique for measuring voltage with a DMM? Connect the DMM in series with the circuit Connect the DMM in parallel with the circuit Use the highest voltage range setting for accurate measurements Keep the circuit powered on while taking voltage measurements Hint 46). Which mode should you select on a DMM to measure current in a circuit? Voltage mode Resistance mode Current mode Power mode Hint 47). If the current being measured exceeds the range selected on the DMM, what is likely to happen? The DMM will display an error message. The DMM will automatically switch to a higher range. The DMM will automatically switch to a lower range. The DMM will display an inaccurate reading. Hint 48). When connecting a DMM in series to measure current, how should the DMM be connected in the circuit? In parallel with the load In series with the load Across the power supply Across the ground connection Hint 49). If a DMM has multiple current ranges (e.g., 200mA, 2A, 10A), which range should you initially select to measure a current of 400mA? 200mA 2A 10A It doesn't matter which range you choose. Hint 50). What is the typical input impedance of a DMM when measuring current? High impedance Low impedance Variable impedance No impedance Hint For More MCQs Kirchhoff’s Law Question & Answers. Ohms Law Question & Answers. . Time's up