Moving Iron Instrument Question & AnswersJune 24, 2023 By Wat Electrical This article lists 75 Moving Iron Instrument MCQs for engineering students. All the Moving Iron Instrument 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 Moving Iron Instrument.A moving iron instrument is a type of electrical measuring instrument used for the measurement of AC and DC currents and voltages. It operates based on the principle of magnetic attraction or repulsion between a fixed coil or magnet and a movable iron piece or vane. The principle behind the operation of a moving iron instrument is that when current flows through a coil, it generates a magnetic field. This magnetic field interacts with a movable iron piece or vane, causing it to move.Moving iron instruments consist of a stationary coil wound on a soft iron core and a movable iron piece or vane. The iron vane is typically mounted on a spindle and is free to move in response to the magnetic field generated by the coil.Moving iron instruments are commonly used in various electrical and electronic systems for measuring currents and voltages. They are used in power systems, laboratories, industrial applications, and in the field of audio and communications. 1). A moving iron based instrument, the movement of the iron piece is based on the principle of ___________________? Electromagnetic induction Magnetic repulsion Magnetic attraction Electrostatic force None Hint2). Moving iron instruments are primarily used for the measurement of ____________________? Only AC currents Only DC currents Both AC and DC currents Only voltage None Hint3). The construction of a moving iron instrument includes a stationary coil wound on a _________________? Copper core Aluminum core Soft iron core Steel core None Hint4). Moving iron instruments can be classified into two types based on the interaction between the coils and iron piece: attraction type and __________________? Induction type Repulsion type Electromagnetic type Suspension type None Hint5). The movement of the iron piece in a moving iron instrument is proportional to __________________? Voltage being measured Current being measured Resistance being measured Power being measured None Hint6). Moving iron instruments have a ____________ scale for indicating the measured value? Linear Logarithmic Non-linear Exponential None Hint7). Moving iron instruments are known for their _________________? High accuracy High precision Wide measurement range Digital display None Hint8). The accuracy of moving iron instruments is affected by ________________________? Hysteresis and temperature variations Magnetic field strength Coil resistance Voltage fluctuations None HintRead more about Hysteresis 9). Moving iron instruments are commonly used in ________________? Power generation plants Audio systems Laboratories All of the above None Hint10). The primary advantage of moving iron instruments is their _________________? High accuracy Small size Low cost Wide measurement range None Hint11). Who is credited with the invention of the moving iron instrument? William Duddell Charles Wheatstone Max Planck Albert Einstein None Hint12). In which year was the moving iron instrument invented? 2000 2020 2018 1888 None Hint13). The moving iron instrument was initially developed for the measurement of ________________? DC currents AC currents Both a and b None of the above None Hint14). The first moving iron instruments were mainly used in _________________? Telecommunications Electronics Power distribution systems All of the above None Hint15). What is the basic principle behind the operation of a moving iron instrument? Ohms law Kirchhoff’s law Magnetic attraction Both a and b None Hint16). Who made significant improvements to the moving iron instrument design in the early 20th century? Gustav Kirchhoff Max Planck Joseph Henry Oliver Heaviside None Hint17). Moving iron instruments were commonly used in the early days of electricity alongside ________________? Electrical instruments Electronic instruments Mechanical instruments Electrostatic instruments None Hint18). The movable iron piece in a moving iron instrument is often referred to as ________________? Copper Silicon Iron All of the above None Hint19). In a moving iron based instrument, the deflecting based torque is proportional to __________________? Current passing through the coil Square of the current passing through the coil Voltage across the coil Resistance of the coil None Hint20). The damping torque in a moving iron instrument is usually provided by ___________________? Gravity Springs Magnetic forces Electrical resistance None Hint21). The deflection of a moving iron instrument is __________ with the square of the current. Directly proportional Inversely proportional Linearly proportional Not related None Hint22). Moving iron instruments are suitable for measuring ___________________? AC currents only DC currents only Both AC and DC currents Voltage only None Hint23). The iron piece in a moving iron instrument is generally ___________________? Magnetic Non-magnetic Superconducting Non-conductive None Hint24). The operating principle of a moving iron instrument is based on _____________________? Electrostatic forces Electromagnetic induction Piezoelectric effect Photoelectric effect None Hint25). Moving iron instruments are commonly used for measuring ______________________? Power factor Resistance Capacitance Current None HintMoving Iron Instrument MCQ for Quiz 26). Moving iron instruments have __________________ accuracy compared to moving coil instruments. Higher Lower Equal Variable None Hint None 27). Moving iron instruments are more suitable for measuring ___________________? Low currents High currents Low voltages High voltages None Hint28). The scale of a moving iron instrument is usually __________________? Linear Non-linear Logarithmic Exponential None Hint29). Moving iron instruments are inherently__________________? Self-shielding Non-shielding Sensitive to temperature changes Immune to external magnetic fields None Hint30). Which of the following is a commonly used moving iron instrument device for measuring AC and DC currents? Ammeter Voltmeter Wattmeter Ohmmeter None Hint31). Moving iron instrument devices are primarily based on the principle of __________________? Electrostatics Electromagnetism Piezoelectricity Photoconductivity None Hint32). Which of the following moving iron instrument devices is used for measuring power in an AC circuit? Ammeter Voltmeter Wattmeter Ohmmeter None Hint33). A moving iron instrument device consists of _______________? Moving coil and permanent magnet Moving iron piece and coil Moving iron and spring Moving coil and iron core None Hint34). Which of the following moving iron instrument devices is used for measuring voltage? Ammeter Voltmeter Wattmeter Ohmmeter None Hint35). Moving iron instrument devices are generally suitable for measuring __________________? Low currents High currents Low voltages High voltages None Hint36). Which of the following moving iron instrument devices is used for measuring resistance? Ammeter Voltmeter Wattmeter Ohmmeter None Hint37). Moving iron instrument devices are commonly used in ______________? Laboratories Power plants Residential homes Telecommunication networks None Hint38). The deflection of a moving iron instrument device is proportional to the __________ flowing through the coil? Voltage Current Power Resistance None Hint39). Moving iron instrument devices are often used for power measurement due to their ability to handle ________________? High currents High voltages High resistances High power factors None Hint40). The formula for the deflecting torque in a moving iron instrument is _________________? T = BIL T = kx T = mg T = I/R None Hint41). The formula for the controlling torque in a moving iron instrument is _________________? T = BIL T = kx T = mg None Hint42). The net torque in a moving iron instrument is given by the equation _______________? Net torque = Deflecting torque - Controlling torque Net torque = Deflecting torque + Controlling torque Net torque = Deflecting torque / Controlling torque Net torque = Deflecting torque x Controlling torque None Hint43). The formula for the deflection angle in a moving iron instrument is __________________? θ = kx θ = BIL θ = mg θ = I/R None Hint44). The equation for the damping torque in a moving iron instrument affected by eddy currents is _________________? T = kx T = mg T = I/R T = kω None Hint45). The equation for the total torque in a moving iron instrument is ____________________? Total torque = Net torque + Damping torque Total torque = Net torque - Damping torque Total torque = Net torque x Damping torque Total torque = Net torque / Damping torque None Hint46). The equation for the sensitivity of a moving iron instrument is given by __________________? Sensitivity = (Net torque + Damping torque) / Current Sensitivity = Net torque / Current Sensitivity = Deflecting torque / Current Sensitivity = Deflecting torque / Current None Hint47). The deflection angle of a moving iron instrument is given by the equation ________________? θ = kI θ = kI^2 θ = kV θ = kV^2 None Hint48). The damping torque in a moving iron instrument is given by the equation ________________? Td = kθ Td = kθ^2 Td = kI Td = kI^2 None Hint49). The net deflecting torque in a moving iron instrument is given by the equation ________________? Tn = Td – TC Tn = TD + TC Tn = TD – TC None Hint50). The scale of a moving iron instrument is calibrated using a ________________? Voltmeter Multimeter Standard resistor Reference current source None HintMoving Iron Instrument MCQ for Exams 51). The current sensitivity of a moving iron instrument is defined as ___________________? The ratio of voltage to current The ratio of deflection angle to current The ratio of deflection angle to voltage The ratio of voltage to deflection angle None Hint52). The voltage sensitivity of a moving iron instrument is defined as ___________________? The ratio of voltage to current The ratio of deflection angle to voltage The ratio of voltage to deflection angle None Hint53). The typical problem range of a moving iron ammeter is ___________________? 0-10 A 0-100 A 0-1000 A 0-10,000 A None Hint54). The problem range of a moving iron voltmeter is usually ___________________? 0-10 V 0-100 V 0-1000 V 0-10,000 V None Hint55). The problem range of a moving iron wattmeter is commonly ___________________? 0-1 W 0-100 W 0-1000 W 0-10,000 V None Hint55). The problem range of a moving iron wattmeter is commonly ___________________? 0-1 W 0-100 W 0-1000 W 0-10,000 W None Hint56). The problem range of a moving iron power factor meter is typically ___________________? 0-0.5 lagging to 0.5 leading 0-0.8 lagging to 0.8 leading 0-1 lagging to 1 leading 0-2 lagging to 2 leading None Hint57). The problem range of a moving iron frequency meter is generally ________________? 0-10 Hz 0-100 Hz 0-1000 Hz 0-10,000 Hz None Hint58). The problem range of a moving iron ohmmeter is typically ________________? 0-1 Ω 0-100 Ω 0-1000 Ω 0-10,000 Ω None Hint59). The problem range of a moving iron meter for measuring reactive power (VAR) is typically ________________? 0-1 VAR 0-100 VAR 0-1000 VAR 0-10,000 VAR None Hint60). The problem of non-linearity in a moving iron instrument can be addressed by ________________? Using a more sensitive coil Applying calibration curves Increasing the resistance of the coil Decreasing the number of turns in the coil None Hint61). Moving iron instruments are typically designed to operate within a temperature range of ___________________? -20°C to 50°C 0°C to 100°C -40°C to 85°C -10°C to 70°C None Hint62). The temperature range of moving iron instruments is primarily determined by the ___________________? Coil material Iron piece material Damping mechanism Spring material None Hint63). Moving iron instruments are designed to withstand a wide temperature range to ensure ___________________? Accurate measurements Durability and reliability Compatibility with different environments Energy efficiency None Hint64). The temperature coefficient of a moving iron instrument refers to its ___________________? Sensitivity to temperature changes Rate of deflection with temperature variations Thermal expansion coefficient Heat dissipation capability None Hint65). The temperature range specification of a moving iron instrument is usually provided by the ___________________? Manufacturer's datasheet International standards organization Calibration laboratory Regulatory agency None Hint66). High-temperature moving iron instruments often incorporate additional measures such as ___________________? Cooling fans Heat sinks Thermoelectric cooling Insulation blankets None Hint67). The temperature range of a moving iron instrument can impact its ___________________? Accuracy Sensitivity Linearity All of the above None Hint68). The temperature range of a moving iron instrument is crucial in applications where ___________________? Wide temperature variations are expected High precision is required Low power consumption is desired High resistance materials are used None Hint69). The temperature range of moving iron instruments is often tested and certified through ___________________? Calibration procedures Thermal imaging techniques Accelerated aging tests Environmental chambers None Hint70). The temperature range of a moving iron instrument can affect its internal components, such as ___________________? Coil resistance Spring stiffness Magnetic properties of the iron piece All of the above None Hint71). Moving iron instruments are typically used for measuring frequencies up to ___________________? 1 Hz 10 Hz 100 Hz 1 kHz None Hint72). The frequency response of a moving iron instrument is primarily limited by ________________? Coil resistance Magnetic field strength Eddy currents Damping torque None Hint73). Moving iron instruments can measure frequencies in the range of ________________? DC only DC to 50 Hz DC to 100 Hz DC to 1 kHz None Hint74). The response of a moving iron instrument becomes progressively weaker beyond its frequency range due to ________________? Coil resistance Eddy currents Hysteresis Saturation of the iron core None Hint75). Moving iron instruments are generally not suitable for measuring frequencies above ________________? 50 Hz 100 Hz 1 kHz 10 kHz None Hint Time's up
