Description : n electrochemical cell which is used as a source of direct electrical current at constant voltage under standard conditions is called a – (1) Power transmittor (2) Battery (3) Uninterrupted power supply (UPS) (4) Generator
Last Answer : (3) Uninterrupted power supply (UPS) Explanation: A Galvanic cell, also known as battery, is an electro-chemical cell that derives electrical energy from spontaneous redox reactions taking place within ... produce direct current. A battery is a set of galvanic cells that are connected in parallel.
Description : Which one of the following statements is not correct? A Since voltage depends on concentrations, using standard conditions makes it easier to compare different electrochemical reactions. B We have ... half-reactions are determined by combining the relevant half-cell with a standardised half-cell.
Last Answer : C The direction of a redox reaction can only be determined experimentally.
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
Last Answer : Answer: C
Description : What is USP in marketing field? (1) Uninterrupted power supply (2) Universal standards of production (3) Us Programme based (4) Exclusive marketing features
Last Answer : (4) Exclusive marketing features Explanation: The Unique Selling Proposition (a.k.a. Unique Selling Point, or USP) Is a marketing concept that was first proposed as a theory to understand a pattern ... convinced them to switch brands. The term was invented by Rosser Reeves of Ted Bates & Company.
Description : The source of emergency lighting and power at loss of normal ship's power on a cargo vessel should be obtained from the ______________. A. emergency generator supply to the emergency ... switchboard C. battery supply to the main switchboard D. turbogenerator supply to the emergency switchboard
Last Answer : Answer: A
Description : One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for ... placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections
Last Answer : Answer: B
Description : Two half-reactions of an electrochemical cell are given below : MnO-4 (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (I), E° = 1.51 V Sn2+ (aq) → Sn4+ (aq) + 2e- ... the redox equation from the standard potential of the cell and predict if the reaction is reactant favoured or product favoured. -Chemistry
Last Answer : The reactions can be represented at anode and at cathode in the following ways : At anode (oxidation) : Sn2+ → = Sn4+ (aq) + 2e- ] 5 E° = + 0.15 V At cathode (reduction) : MnO-4(aq) + 8H+ ... = E°cathode - E°anode = 1.51 - 0.15 = + 1.36 V ∴ Positive value of E°cell favours formation of product.
Description : Two half-reactions of an electrochemical cell are given below : MnO-4 (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (I), E° = 1.51 V Sn2+ (aq) → Sn4+ (aq) + ... -reactions and calculate the cell potential from the standard potentials and predict if the reaction is reactant or product favoured. -Chemistry
Last Answer : The reactions can be represented at anode and at cathode in the following ways : At anode (oxidation) : Sn2+ → Sn4+ (aq) + 2e- ] 5 E° = + 0.15 V Af cathode (reduction) : MnO-4(aq) + 8H+ ( ... = E°cathode - E°anode = 1.51 - 0.15 = + 1.36 V ∴ Positive value of E°cell favours formation of product.
Description : The battery has following three major functions to perform: a) To provide a source of current for engine starting, lighting and use of horn. b) To help control the voltage in the electrical system. c ... the current produced by dynamo/alternator and to furnish the current d) all of the above. Ans. d
Last Answer : ans d
Description : Which of the listed sections of an emergency switchboard is used to supply power for alarm signals under emergency conditions? A. The generator and bus transfer section B. The 450 volt, 60 cycle, 3 phase bus C. The 120 volt, 3 phase, 60 cycle bus D. The 24 volt DC bus
Last Answer : Answer: D
Description : Load regulation is a measure of a power supplies ability keep a constant output under conditions of changing A) Line voltage B) Current demand C) Temperature D) Oscillator frequency.
Last Answer : A) Line voltage
Description : The rusting of iron is a/an - (1) physical change (2) electrochemical change (3) electrical change (4) None of the above
Last Answer : (2) electrochemical change Explanation: When iron is exposed to air and moisture, its surface gradually corroded and converted into a brown mass. The rusting of iron is due to the formation of hydrated ion. Rusting is an electro-chemical process.
Description : The rusting of iron is a/an (1) physical change (2) electrochemical change (3) electrical change (4) None of the above
Last Answer : electrochemical change
Description : A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an _____________. A. rotor B. stator C. exciter D. armature
Description : UPS is now widely use in households. What does UPS stands for ? A. Uniform Power Storage B. Universal Product Support C. Under Panel Storage D. Uninterruptible Power Supply (Answer)
Last Answer : D. Uninterruptible Power Supply (Answer)
Description : Under which of the following conditions will a lead-acid battery be given a 'test discharge'? A. To determine its capacity. B. Whenever a cell cannot be brought within 10 points of full charge ... cells is found to have less than normal voltage after an equalizing charge. D. All of the above.
Description : Direct conversion of chemical energy into electrical energy is done in a (A) Magnetohydrodynamic (MHD) generator (B) Fuel cell (C) Fast breeder reactor (D) None of these
Last Answer : (B) Fuel cell
Description : Direct conversion of thermal energy to electrical energy is facilitated by the (A) Fuel cells (B) Photo voltaic cell (C) Magneto hydrodynamic generator (D) None of these
Last Answer : (C) Magneto hydrodynamic generator
Description : The distance between a generator and its load is 100 feet. What would be the approximate total voltage drop across a two wire supply cable if the current were 5.5 amperes and the resistance of the wire were 2.525 ohms per 1,000 feet? A. 0.5 volts B. 1.38 volts C. 1.90 volts D. 2.77 volts
Description : A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of ... . (B) more than 800 rpm. (C) less than 800 rpm. (D) both higher or lower than 800 rpm.
Last Answer : (C) less than 800 rpm.
Description : Which of the following statements is true about the illustrated circuit? EL-0030 A. The field rheostat is used for manual voltage control. B. if the generator is flat compounded then the field rheostat ... to act like a series motor and overspeed with the controller in the full raise position.
Description : In the illustration, the component labeled 'EXC' is _______. EL-0003 A. a separate class II regulated DC generator for critical direct current loads B. a generator feeding the FLD ... to drive the governor for turbogenerator speed. D. the electronic driver for the switchboard metering circuits
Description : The purpose of the commutator and brushes on a DC generator is to _____________. A. transfer generated direct current voltage from the armature to the line B. convert the alternating voltage ... contact method to excite the field D. reduce sparking between the armature and the carbon brushes
Description : In an AC generator, direct current from a separate source is passed through the windings of the rotor _____________. A. by means of slip rings and brushes B. by means of a commutator C. by means of rotating bar magnet D. to minimize the danger of arc over
Description : When troubleshooting electronic equipment, the FIRST step to be taken before testing the circuit voltage is to _________. A. set the meter to the lowest range B. check the voltage supply from the power source C. remove the suspected component D. check the current flow through the circuit
Description : An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from ... C. any suitable ground to any available line lead D. any field pole to each field coil lead
Description : What to do to get uninterrupted power ?
Last Answer : If the voltage difference between the two metallic objects is maintained, the electric current continues to flow uninterruptedly. That is , uninterrupted electricity is available.
Description : A 10-bus power system consists of four generator buses indexed as G1, G2, G3, G4 and six load buses indexed as L2, L2, L3, L4, L5, L6. The generator-bus G1 is connected ... of non linear equations required for solving the load flow problem using Newton-Raphson method in popular form is________.
Last Answer : 14
Description : What is a disadvantage of a direct-current system with respect to supply voltage?
Last Answer : the dc voltage must be generated at the level required by the load.
Description : Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in ... . governor speed droop setting B. voltage regulator C. balance coil D. phase-balance relay
Description : The electrical supply applied to the anodes shown in the illustration is _____________. EL-0090 A. low voltage, high current DC B. low voltage, high current AC C. high voltage, low current DC D. high voltage, low current AC
Description : The shipboard general alarm system must receive its main source of power from _____________. A. a storage battery B. the emergency generator C. an auxiliary generator D. the ship's service generator
Description : What is meant by Electrochemical cell . Why is it called as galvanic cell and Voltaic cell ?
Last Answer : Ans. :- The cell which converts chemical energy into electrical energy . It is called as galvanic cell and Voltaic cell after the name of scientists who first tried to convert chemical energy into electrical energy .
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 : 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
Description : Protective relays are devices that detect abnormal conditions in electrical circuits by measuring (a) current during abnormal condition (b) voltage during abnormal condition (c) constantly the electrical quantities which differ during normal and abnormal conditions (d) none of the above
Last Answer : (c) constantly the electrical quantities which differ during normal and abnormal conditions
Description : What features should I look for in a UPS (uninterruptible power supply)?
Last Answer : answer:If that's all you need the UPS for: to handle tiny burps' in the power supply, then you can get by with the cheapest, most generic UPS that you can find. Seriously. You need next to ... 'd have switched to a laptop long ago (which is my home computer now, anyway) for just that reason.
Description : For how long 220 V DC batteries can supply power UPS?
Last Answer : 220 V DC batteries can supply Power UPS for 30 minutes. Within this time class III power supply should be restored by DG’s.
Description : ________carries fans and a special port designed for power supply. a) UPS b) Mother Board c) Monitor d) None of These
Last Answer : b) Mother Board
Description : What is Electrochemical Cell ?
Last Answer : Electrochemical cell is a type of cell through which electricity can be generated from chemical energy.
Description : What would happen if salt bridge is not used in electrochemical cell ?
Last Answer : Ans. :- The cell works for short time .After that electrons stop flowing from anode to cathode due to accumulation of +ve ions at anode and no reduction will occur at cathode . The result is that current stops flowing and cell will not work .
Description : What is the principle of electrochemical cell ?
Last Answer : Ans .:- The cell works on the principle of redox reactions . One of the reactant undergoes oxidation while another undergoes reduction
Description : Why cation present below in electrochemical series can discharge before the elements present above them in an electrochemical cell?
Last Answer : Ans: This is because their ability to be reduced (reduction potential) is more than the cation present above them in electrochemical series. So they take electrons before the other cations and get discharged.
Description : What is the purpose of the salt bridge in an electrochemical cell? w) It allows ion migration. x) It allows electron flow. y) It prevents ion migration. z) It prevents electron flow.
Last Answer : ANSWER: W -- IT ALLOWS ION MIGRATION
Description : The most common source of AC voltage is: a. motor b. generator c. cell d. transformer
Last Answer : c. cell
Description : A constant output voltage from an AC generator is maintained by the _____________. A. prime mover governor B. exciter generator C. voltage regulator D. reverse power relay
Description : When charging a 100 amp-hour lead-acid battery, ___________. A. the temperature of the electrolyte should not be allowed to exceed 90°F B. the charging rate should be no greater than 125% of the ... nearing full charge and it will be necessary to reduce the charging current to a low finishing rate
Description : What are the isolated variables and the uninterrupted variables ?
Last Answer : Isolated variable: A variable whose value is only an integer is called an isolated variable. Example: Population. Continuous variable: The value of a variable that can be any real number is a continuous variable. Examples: age , height , weight.
Description : What is the uninterrupted flow of electrons ?
Last Answer : The uninterrupted flow of electrons is called electric current
Description : Known as the data transfer scheme that used handmaking principle. A. Synchronous data transfer scheme B. DMA data transfer scheme C. Asynchronous data transfer scheme D. Uninterrupted data transfer scheme
Last Answer : A. Synchronous data transfer scheme