Description : A device that converts mechanical energy into electric energy is called----? A. Motor. B. Transformer. C. Coil. D. Generator?
Last Answer : B. Transformer.
Description : Alternating current generator converts.......... energy into electrical energy? a. mechanical energy b. chemical energy c. solar energy d. potential energy
Last Answer : a. mechanical energy
Description : Briefly explain how an electrical generator converts mechanical energy into electrical energy.
Last Answer : Working principle of DC generator: * Working principle of DC generator is the principle of dynamically induced emf or electromagnetic induction. * According to this principle, when flux is cut by a conductor, an ... , the flux is cut by the armature winding and an emf is dynamically induced in it.
Description : A transformer – (1) converts DC to AC (2) is used to decrease or increase AC voltage (3) converts AC voltage to D.C. voltage (4) converts electrical energy into mechanical energy
Last Answer : (2) is used to decrease or increase AC voltage Explanation: Transformers have made longdistance transmission of electric power a practical reality, as AC voltage can be "stepped up" and ... the loads), voltage levels are reduced by transformers for safer operation and less expensive equipment.
Description : A transformer (1) converts DC to AC (2) is used to decrease or increase AC voltage (3) converts AC voltage to D.C. voltage (4) converts electrical energy into mechanical energy
Last Answer : is used to decrease or increase AC voltage
Description : The most common source of AC voltage is: a. motor b. generator c. cell d. transformer
Last Answer : c. cell
Description : Which of the following devices converts electrical energy into mechanical energy? (a) Dynamo (b) Transformer (c) Electric motor (d) Inductor
Last Answer : Ans:(c)
Description : A transformer in an electric circuit serves to ____________. A. generate its own electrical power B. transform electrical energy into mechanical energy C. increase or decrease circuit voltage as required D. convert AC current to DC current
Last Answer : Answer: C
Description : The only difference between construction of DC generator and Ac generator is that of: a. carbon brush b. Bar magnet c. electromagnet d. Horseshoe magnet
Last Answer : b. Bar magnet
Description : DC motors converts electrical into ___ energy. A. Mechanical B. Wind C. Electric D. None
Last Answer : A. Mechanical
Description : Explain what happens if a DC motor is fed with AC supply
Last Answer : Motor will run at low speed, sparking at brushes, heat due to eddy current will finally burn the motor.
Description : The electric motor converts - (1) Electrical energy into mechanical energy (2) Mechanical energy into electrical energy (3) Electrical energy into light energy (4) None of these
Last Answer : (1) Electrical energy into mechanical energy Explanation: A generator converts mechanical energy into electrical energy, while a motor does the opposite - it converts electrical energy into mechanical energy.
Description : The process of conversion of AC into DC is called (a) Amplification (b) rectification (c) purification (d)magnification
Last Answer : (b) rectification
Description : What purpose does a generator serve in a hybrid vehicle? (a) It converts nuclear energy 6more nuclear energy. (b)It converts mechanical energy into electrical energy. (c) It converts chemical energy into electrical energy. (d)It converts electrical energy into mechanical energy.
Last Answer : (b)It converts mechanical energy into electrical energy.
Description : Which component is mainly used in a DC generator: a.slip ring b. commutator c. magnet d. coil
Last Answer : b. commutator
Description : What are the parts of a brushless AC generator?
Last Answer : Yoke, armature, stator, rotor, primary exciter, main exciter, rotary diode rectifier assembly, impeller, bearing & housing, end cover, terminal block, AVR.
Description : In the plane of AC generator coil is parallel to the field, then emf induced in coil is: a. maximum b. minimum c. zero d. intermediate
Last Answer : b. minimum
Description : Which one is not present in AC generator: a. Armature b. magnet c. slip ring d. commutator
Last Answer : c. slip ring
Description : The principle of AC generator is: a. Mutual induction b. self induction c. electromagnetic induction d. Induction
Last Answer : b. self induction
Description : What do we use for welding on ships? AC or DC?
Last Answer : Ask E/O on your ship.
Description : The output from a full wave rectifier is (a) A pulsating uni-directional current (b) A DC voltage (c) Zero (d) An AC voltage
Last Answer : a) A pulsating uni-directional current
Description : In a half wave rectifier the rms value of AC component of the waves (a) Zero (b) Equal to DC value (c) More than DC value (d) Less than DC value
Last Answer : b) Equal to DC value
Description : Turn ratio of a transformer is 5. If 220 V AC is applied to its primary coil, voltage in the secondary coil will be: a. 44V b. 4.4 V c. 220V d. 1100V
Last Answer : c. 220V
Description : The device used for converting mechanical energy into electrical energy is called a/an (a) cell (b) transformer (c) dynamo (d) electric motor
Description : A thermoelectric engine which consists of two dissimilar electric conductors connected at two junctions maintained at different temperatures, converts (a) Electric energy into heat energy [IES-2006] (b ... energy (c) Mechanical work into electric energy (d) Electric energy into mechanical work
Last Answer : (b) Heat energy into electric energy
Description : What are the basic parts of a DC motor?*
Last Answer : Rotor and stator, field poles, commutator, brushes, fan impeller, bearing & housing, end covers and name plate.
Description : How is the speed of a DC motor varied?
Last Answer : To vary the speed of a DC motor we need a constant voltage power supply with a series POT resistor of higher watt rating. A Pulse Width Modulator (PWM) can be used.
Description : Where is a rotor wound AC motor used?
Last Answer : For starting heavy torques, mostly used on portable machines and small winches.
Description : How can the direction of rotation of an AC motor be reversed?*
Last Answer : By interchanging any two supply lines.
Description : A device which converts chemical energy into electrical energy is called -----? A. motor B. generator C. moving-coil meter D. battery (Answer)
Last Answer : D. battery (Answer)
Description : Why are motor ratings given in KW and that of alternator and transformer given in KVA?
Last Answer : kW is the output mechanical power of a motor and is expressed in kW. kVA is the net (apparent) power input to the transformer. This input power is the output + losses. kW = kVA x system power factor
Description : The application of mutual induction is: a. TV b. Radio c. Transformer d. Motor
Last Answer : c. Transformer
Description : The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply
Description : Which of the listed electrical devices is represented by the symbol shown in the illustration? EL-0055 A. Fixed resistance resistor B. Coil with magnetic core C. DC motor or generator shunt field D. Transformer
Last Answer : Answer: D
Description : The purpose of DC generator brushes is to _____________. A. neutralize armature reaction B. conduct electric current to an outside circuit C. convert DC current to AC current D. provide excitation to a DC generator
Last Answer : Answer: B
Description : A photoelectric cell converts – (1) Mechanical energy to electric energy (2) Heat energy to mechanical energy (3) Light energy to chemical energy (4) Light energy to electrical energy
Last Answer : (4) Light energy to electrical energy Explanation: Photoelectric cell or photocell, device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident ... The most common type consists of two electrodes separated by a light-sensitive semiconductor material.
Description : A photo-electric cell converts (1) mechanical energy to electric energy (2) heat energy to mechanical energy (3) light energy to chemical energy (4) light energy to electrical energy
Last Answer : light energy to electrical energy
Description : Thermocouples convert a. heat energy into electrical energy b. heat energy into light energy c. heat energy into mechanical energy d. mechanical energy into heat energy
Last Answer : d. mechanical energy into heat energy
Description : Moisture accumulating in electric motors and generator windings having a cold insulation resistance greater than 50,000 ohms may be baked out with internal heat. This heat can be developed by ____________. ... an electric welder and feeding it into the armature while running the motor at full speed
Last Answer : Answer: A
Description : The device which converts AC to DC is (1) Oscillator (2) Amplifier (3) Rectifier (4) None of these
Last Answer : (3) Rectifier Explanation: A rectifier is an electrical device that converts alternating current (AC). which periodically reverses direction, to direct current (DC), which flows in only one ... serving as components of DC power supplies and high-voltage direct current power transmission systems.
Description : Which of the following is not true: A) An oscillator is a circuit that converts DC to AC B) An oscillator is an amplifier that supplies its own input signal C) All oscillators generate sine waves D) In phase feedback is called positive Feedback
Last Answer : C) All oscillators generate sine waves
Last Answer : Rectifier
Description : Which of the following device converts DC to AC? A) Rectifier B) Boost converter C) Transformer D) Inverter
Last Answer : Reflector
Description : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field
Last Answer : d. gravitational field
Description : In a diesel electric plant, raising the generator's field excitation will cause the DC propulsion motor to ________. A. increase in speed B. decrease in speed C. affect generator speed only D. affect main motor speed if done in conjunction with higher generator engine speeds
Description : On some diesel-electric ships, the DC propulsion motor will only attain half speed when the generator fields are fully excited. Speeds above this are obtained by _____________. A. rotating brush ... B. raising the generator engine speed C. lowering the generator engine speed D. decreasing excitation
Description : In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength
Description : The loss of energy over each A.C cycle magnetization and demagnetization of transformer, is called: a. Magnetization loss b. Hysteresis loss c. Demagnetization loss d. energy loss
Last Answer : c. Demagnetization loss
Description : An ideal transformer always obeys the law of conservation of........: a. energy b. momentum c. charge d. Flux
Last Answer : b. momentum