All Free Electrical Engineering MCQs with Answers
Every Electrical Engineering question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
3,143 questions · page 121 of 158
2401. Which of the following works on torque on the current carrying conductor placed in magnetic field ?
- A. galvanometer
- B. ammeter
- C. voltmeter
- D. all of the above
Explanation: A moving-coil galvanometer produces torque when current-carrying conductors lie in a magnetic field.
Correct answer: all of the above- A. current
- B. voltage
- C. resistance
- D. power
Explanation: A Wheatstone bridge compares resistor ratios and reaches balance when the detector current is zero.
Correct answer: resistance- A. 20,000 Ω
- B. 100,000 Ω
- C. 200,000 Ω
- D. 1,000,000 Ω
Explanation: Voltmeter resistance equals sensitivity multiplied by the selected range: 20,000 Ω/V × 5 V = 100,000 Ω.
Correct answer: 100,000 Ω- A. 1 V
- B. 50 V
- C. 500 V
- D. 1,000 VCompare Power Rates
Explanation: A voltmeter's input resistance is generally highest on its highest voltage range, so it draws the least current from the circuit.
Correct answer: 1,000 VCompare Power Rates- A. Acceleration
- B. Speed
- C. Speed and acceleration
- D. Displacement
- E. None of the above
Explanation: A tachogenerator produces an output voltage proportional to angular velocity, so it is used to measure speed.
Correct answer: Speed- A. Thermocouple
- B. Potentiometer
- C. Gear train
- D. LVDT
- E. None of the above
Explanation: A thermocouple generates a voltage from a temperature difference through the Seebeck effect, directly converting thermal information into…
Correct answer: Thermocouple- A. Alternating current
- B. Direct current
- C. A.C. voltage
- D. D.C. voltage
- E. None of the above
Explanation: A thermocouple converts a temperature difference into a thermoelectric emf, whose polarity is fixed for a given temperature gradient.
Correct answer: D.C. voltage- A. Vernistats
- B. Microsyns
- C. Resolvers
- D. Any of the above
Explanation: Veristats, microsyns, and resolvers can all convert positional error into an electrical signal for comparison and correction.
Correct answer: Any of the above- A. static sensitivity
- B. dynamic deviation
- C. linearity
- D. precision or accuracy
Explanation: Linearity is commonly specified as the maximum deviation from the ideal straight-line response divided by full-scale value, usually…
Correct answer: linearity- A. multiple shunt or series resistances inside the meter
- B. multicoii arrangement
- C. variable turns of coil
- D. multi range meters inside the measurement system
- E. any of the above
Explanation: A multirange meter obtains different ranges by switching suitable shunt resistors for current measurement or series resistors for voltage…
Correct answer: multiple shunt or series resistances inside the meter- A. that it works on the principle of complex variation
- B. that it measures the response of linear ramp voltage
- C. same as digital meter
- D. that it measures the amplitude of a single at two points and at the same time measures their phase difference
Explanation: A vector voltmeter measures the magnitude of a signal and the phase difference between signals at two points, so it gives their voltage…
Correct answer: that it measures the amplitude of a single at two points and at the same time measures their phase difference- A. safe guard it against creep
- B. brake the instrument
- C. bring energy meter to stand still
- D. maintain steady speed and equal to driving torque
Explanation: The driving torque makes the energy-meter disc rotate, while braking torque opposes it until the disc reaches a steady speed.
Correct answer: maintain steady speed and equal to driving torque- A. (n - 1) wattmeter elements
- B. n wattmeter elements
- C. (n + 1) wattmeter elements
- D. 2n wattmeter elements
Explanation: For an n-phase circuit, the total power can be measured with n−1 wattmeters because the sum of the wattmeter readings gives total power.
Correct answer: (n - 1) wattmeter elements- A. Amplifier gain and phase shift
- B. Filler transfer functions
- C. Complex insersion loss
- D. All of the above
Explanation: A vector voltmeter measures both magnitude and phase, allowing gain and phase shift, filter transfer functions, and complex insertion loss…
Correct answer: All of the above- A. light load or friction
- B. lag and creep
- C. overload and voltage compensation
- D. temperature compensation
- E. all of the above
Explanation: Energy meters require several corrections, including friction or light-load adjustment, lag and creep compensation, overload and voltage…
Correct answer: all of the above- A. induction instrument
- B. electrostatic instrument
- C. moving coil instrument
- D. any of the above
Explanation: Current and voltage instrument transformers, such as CTs and PTs, extend the usable range of AC instruments, including induction-type…
Correct answer: induction instrument- A. elastic galvanometer
- B. vibration galvanometer
- C. Duddlb galvanometer
- D. spot ballistic galvanometer
Explanation: A spot ballistic galvanometer uses optical spot deflection and is designed to detect very small quantities of charge, giving very high…
Correct answer: spot ballistic galvanometer- A. instrumental errors
- B. environmental errors
- C. observational errors
- D. all of the above
Explanation: Systematic errors have a consistent cause or pattern and may arise from the instrument, the environment, or the observer.
Correct answer: all of the above- A. deflecting and control
- B. deflecting and damping
- C. deflecting, control and damping
- D. vibration and balancing
Explanation: An analogue instrument needs deflecting torque to produce movement, controlling torque to establish the final position, and damping torque…
Correct answer: deflecting, control and damping- A. balancing weight
- B. deflection angle
- C. sine of deflection angle
Explanation: In a gravity-controlled instrument, controlling torque is proportional to sin θ.
Correct answer: sine of deflection angle