McqMate
Chapters
| 201. |
If I2 be the armature current, then speed of a D.C. shunt motor is |
| A. | independent of Ia |
| B. | proportional to la |
| C. | varies as (Ia) |
| D. | varies as la |
| Answer» A. independent of Ia | |
| 202. |
In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will |
| A. | remain unchanged |
| B. | reduce to one-fourth value |
| C. | increase four folds |
| D. | be doubled |
| Answer» A. remain unchanged | |
| 203. |
At the instant of starting when a D.C. motor is put on supply, it behaveslike |
| A. | a highly resistive circuit |
| B. | a low resistance circuit |
| C. | a capacitive circuit |
| D. | none of the above |
| Answer» B. a low resistance circuit | |
| 204. |
The speed of a D.C. motor can be varied by varying |
| A. | field current |
| B. | applied voltage |
| C. | resistance in series with armature |
| D. | any of the above |
| Answer» D. any of the above | |
| 205. |
Which one of the following is not necessarily the advantage of D.C. motors over A.C. motors ? |
| A. | Low cost |
| B. | Wide speed range |
| C. | Stability |
| D. | High starting torque. |
| Answer» A. Low cost | |
| 206. |
For a D.C. shunt motor if the excitation is changed |
| A. | torque will remain constant |
| B. | torque will change but power will remain constant |
| C. | torque and power both will change |
| D. | torque, power and speed, all will change |
| Answer» B. torque will change but power will remain constant | |
| 207. |
Which motor has the poorest speed control? |
| A. | Differentially compounded motor |
| B. | Cumulatively compoundedmotor |
| C. | Shunt motor |
| D. | Series motor |
| Answer» D. Series motor | |
| 208. |
The plugging gives the |
| A. | zero torque braking |
| B. | smallest torque braking |
| C. | highest torque braking |
| D. | none of the above |
| Answer» C. highest torque braking | |
| 209. |
The armature voltage control of D.C. motor provides |
| A. | constant voltage drive |
| B. | constant current drive |
| C. | constant torque drive |
| D. | none of the above |
| Answer» C. constant torque drive | |
| 210. |
If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor |
| A. | of lower H.P. should be selected |
| B. | of higher H.P. should be selected |
| C. | can be used for 50°C ambient temperature also |
| D. | is to be derated by a factor recom-mended by manufacturer and select the next higher H.P. motor |
| Answer» D. is to be derated by a factor recom-mended by manufacturer and select the next higher H.P. motor | |
| 211. |
If the terminals of armature of D.C. motor are interchanged, this action will offer following kind of braking |
| A. | regenerative |
| B. | plugging |
| C. | dynamic braking |
| D. | none of the above |
| Answer» B. plugging | |
| 212. |
Which of the following motors one will choose to drive the rotary compressor ? |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Universal motor |
| D. | Synchronous motor |
| Answer» D. Synchronous motor | |
| 213. |
If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will |
| A. | increase |
| B. | decrease |
| C. | remain same |
| D. | become zero |
| Answer» A. increase | |
| 214. |
Why are the D.C. motors preferred for traction applications ? |
| A. | Torque and speed are inversely proportional to armature current |
| B. | Torque is proportional to armature current |
| C. | Torque is proportional to square root of armature current |
| D. | The speed is inversely proportional to the torque and the torque is proportional to square of armature current |
| Answer» D. The speed is inversely proportional to the torque and the torque is proportional to square of armature current | |
| 215. |
Which of the following motors is usually used in house-hold refrigerators ? |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Single phase induction motor (split phase start or induction run motor) |
| D. | Reluctance motor |
| Answer» C. Single phase induction motor (split phase start or induction run motor) | |
| 216. |
Which of the following motors is most suitable for signalling devices and many kinds of timers ? |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Induction motor |
| D. | Reluctance motor |
| Answer» D. Reluctance motor | |
| 217. |
Which motor should not be started on no-load ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor. |
| Answer» A. Series motor | |
| 218. |
Ward-Leonard control is basically a |
| A. | voltage control method |
| B. | field divertor method |
| C. | field control method |
| D. | armature resistance control method |
| Answer» A. voltage control method | |
| 219. |
For constant torque drive which speed control method is preferred ? |
| A. | Field control |
| B. | Armature voltage control |
| C. | Shunt armature control |
| D. | Mechanical loading system |
| Answer» B. Armature voltage control | |
| 220. |
In Ward-Leonard control the lower limit of speed is imposed by |
| A. | residual magnetism of the generator |
| B. | core losses of motor |
| C. | mechanical losses of motor and gen¬erator together |
| D. | all of the above |
| Answer» A. residual magnetism of the generator | |
| 221. |
The main disadvantage of the Ward-Leonard control method is |
| A. | high initial cost |
| B. | high maintenance cost |
| C. | low efficiency at Hght loads |
| D. | all of the above |
| Answer» D. all of the above | |
| 222. |
Regenerative method of braking is based on that |
| A. | back e.m.f. is less than the applied voltage |
| B. | back e.m.f. is equal to the applied voltage |
| C. | back e.m.f. of rotor is more than the applied voltage |
| D. | none of the above |
| Answer» B. back e.m.f. is equal to the applied voltage | |
| 223. |
The hysteresis loss in a D.C. machine least depends on |
| A. | Frequency of magnetic reversals |
| B. | Maximum value of flux density |
| C. | Volume and grade of iron |
| D. | Rate of flow of ventilating air |
| Answer» D. Rate of flow of ventilating air | |
| 224. |
In a D.C. generator all of the following could be the effects of iron losses except |
| A. | Loss of efficiency |
| B. | Excessive heating of core |
| C. | Increase in terminal voltage |
| D. | Rise in temperature of ventilating air |
| Answer» C. Increase in terminal voltage | |
| 225. |
The losses occurring in a D.C. generator are given below. Which loss is likely to have highest proportion at rated load of the generator ? |
| A. | hysteresis loss |
| B. | field copper loss |
| C. | armature copper loss |
| D. | eddy current loss |
| Answer» C. armature copper loss | |
| 226. |
Which of the following loss in a D.C. generator varies significantly with the load current ? |
| A. | Field copper loss |
| B. | Windage loss |
| C. | Armature copper loss |
| D. | None of the above |
| Answer» C. Armature copper loss | |
| 227. |
Torque developed by a D.C. motor depends upon |
| A. | magnetic field |
| B. | active length of the conductor |
| C. | current flow through the conductors |
| D. | all above factors |
| Answer» D. all above factors | |
| 228. |
D.C. shunt motors are used for driving |
| A. | trains |
| B. | cranes |
| C. | hoists |
| D. | machine tools |
| Answer» D. machine tools | |
| 229. |
In a manual shunt motor starter |
| A. | over load relay is connected in series and no volt relay in parallel with the load |
| B. | over load relay is connected in paral¬lel and no volt relay in series with the load |
| C. | over load relay and no volt relay are both connected in series with the load |
| D. | over load relay and no volt relay are both connected in parallel with the load |
| Answer» A. over load relay is connected in series and no volt relay in parallel with the load | |
| 230. |
Which of the following steps is likely to result in reduction of hysteresis loss in a D.C. generator ? |
| A. | Providing laminations in armature core |
| B. | Providing laminations in stator |
| C. | Using non-magnetic material for frame |
| D. | Using material of low hysteresis co-efficient for armature corematerial |
| Answer» D. Using material of low hysteresis co-efficient for armature corematerial | |
| 231. |
Which of the following loss in a D.C. generator is dissipated in the form of heat? |
| A. | Mechanical loss |
| B. | Core loss |
| C. | Copper loss |
| D. | All of the above |
| Answer» D. All of the above | |
| 232. |
Which of the following losses are significantly reduced by laminating the core of a D.C. generator ? |
| A. | Hysteresis losses |
| B. | Eddy current losses |
| C. | Copper losses |
| D. | Windage losses |
| Answer» B. Eddy current losses | |
| 233. |
The total losses in a well designed D.C. generator of 10 kW will be nearly |
| A. | 100 W |
| B. | 500 W |
| C. | 1000 W |
| D. | 1500 W |
| Answer» B. 500 W | |
| 234. |
The condition for maximum efficiency for a D.C. generator is |
| A. | eddy current losses = stray losses |
| B. | hysteresis losses = eddy current losses |
| C. | copper losses = 0 |
| D. | variable losses = constant losses |
| Answer» D. variable losses = constant losses | |
| 235. |
D.C. generators are normally designed for maximum efficiency around |
| A. | full-load |
| B. | rated r.p.m. |
| C. | rated voltage |
| D. | all of the above |
| Answer» A. full-load | |
| 236. |
In a D.C. generator, the iron losses mainly take place in |
| A. | yoke |
| B. | commutator |
| C. | armature conductors |
| D. | armature rotor |
| Answer» D. armature rotor | |
| 237. |
D.C. generators are installed near the load centres to reduce |
| A. | iron losses |
| B. | line losses |
| C. | sparking |
| D. | corona losses |
| Answer» B. line losses | |
| 238. |
The purpose of retardation test on D.C. shunt machines is to find out |
| A. | stray losses |
| B. | eddy current losses |
| C. | field copper losses |
| D. | windage losses |
| Answer» A. stray losses | |
| 239. |
Which of the following tests will be suitable for testing two similar D.C. series motors of large capacity ? |
| A. | Swinburne'stest |
| B. | Hopkinson'stest |
| C. | Field test |
| D. | Brake test |
| Answer» C. Field test | |
| 240. |
Hopkinson's test on D.C. machines is conducted at |
| A. | no-load |
| B. | part load |
| C. | full-load |
| D. | overload |
| Answer» C. full-load | |
| 241. |
During rheostat braking of D.C. series motors |
| A. | motor is run as a generator |
| B. | motor is reversed in direction |
| C. | motor is run at reduced speed |
| D. | all |
| Answer» A. motor is run as a generator | |
| 242. |
For which types of D.C. motor, dynamic braking is generally used ? |
| A. | Shunt motors |
| B. | Series motors |
| C. | Compound motors |
| D. | All of the above |
| Answer» D. All of the above | |
| 243. |
Which method of braking is generally used in elevators ? |
| A. | Plugging |
| B. | Regenerative braking |
| C. | Rheostatic braking |
| D. | None of the above |
| Answer» A. Plugging | |
| 244. |
In variable speed motor |
| A. | a stronger commutating field is needed at low speed than at high speed |
| B. | a weaker commutating field is needed at low speed than at high speed |
| C. | same commutating field is needed at low speed than at high speed |
| D. | none of the above is correct |
| Answer» B. a weaker commutating field is needed at low speed than at high speed | |
| 245. |
When the armature of a D.C. motor rotates, e.m.f. induced is |
| A. | self-induced e.m.f. |
| B. | mutually induced e.m.f. |
| C. | back e.m.f. |
| D. | none of the above |
| Answer» C. back e.m.f. | |
| 246. |
Where D.C. motor of H.P. 12 or more requires frequent starting, stopping,reversing and speed control |
| A. | drum type controller is used |
| B. | three point starter is used |
| C. | four point starter is used |
| D. | all above can be used |
| Answer» A. drum type controller is used | |
| 247. |
If a D.C. shunt motor is working at full load and if shunt field circuit suddenlyopens |
| A. | this will make armature to take heavy current, possibly burning it |
| B. | this will result in excessive speed, possibly destroying armature due toexcessive centrifugal stresses |
| C. | nothing will happen to motor |
| D. | motor will come to stop |
| Answer» A. this will make armature to take heavy current, possibly burning it | |
| 248. |
D.C. motor is to drive a load which has certain minimum value for most of thetime and some peak value for short duration. We will select the |
| A. | series motor |
| B. | shunt motor |
| C. | compound motor |
| D. | any of the above |
| Answer» A. series motor | |
| 249. |
D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select this |
| A. | series motor |
| B. | shunt motor |
| C. | compound motor |
| D. | any of the above |
| Answer» C. compound motor | |
| 250. |
Which D.C. motor has got maximum self relieving property ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor |
| Answer» A. Series motor | |
| 251. |
In the D.C. motor the iron losses occur in |
| A. | the field |
| B. | the armature |
| C. | the brushes |
| D. | the commutator |
| Answer» B. the armature | |
| 252. |
Laminations of core are generally made of |
| A. | case iron |
| B. | carbon |
| C. | silicon steel |
| D. | stainless steel |
| Answer» C. silicon steel | |
| 253. |
Which of the following could be lamina-proximately the thickness of laminations of a D.C. machine ? |
| A. | 0.005 mm |
| B. | 0.05 mm |
| C. | 0.5 m |
| D. | 5 m |
| Answer» C. 0.5 m | |
| 254. |
The armature of D.C. generator is laminated to |
| A. | reduce the bulk |
| B. | provide the bulk |
| C. | insulate the core |
| D. | reduce eddy current loss |
| Answer» D. reduce eddy current loss | |
| 255. |
The resistance of armature winding depends on |
| A. | length of conductor |
| B. | cross-sectional area of the conductor |
| C. | number of conductors |
| D. | all of the above |
| Answer» D. all of the above | |
| 256. |
The field coils of D.C. generator are usually made of |
| A. | mica |
| B. | copper |
| C. | cast iron |
| D. | carbon |
| Answer» B. copper | |
| 257. |
The commutator segments are connected to the armature conductors by means of |
| A. | copper lugs |
| B. | resistance wires |
| C. | insulation pads |
| D. | brazing |
| Answer» A. copper lugs | |
| 258. |
In a commutator |
| A. | copper is harder than mica |
| B. | mica and copper are equally hard |
| C. | mica is harder than copper |
| D. | none of the above |
| Answer» C. mica is harder than copper | |
| 259. |
In D.C. generators the pole shoes are fastened to the pole core by |
| A. | rivets |
| B. | counter sunk screws |
| C. | brazing |
| D. | welding |
| Answer» B. counter sunk screws | |
| 260. |
Satisfactory commutation of D.C. machines requires |
| A. | brushes should be of proper grade and size |
| B. | brushes should smoothly run in the holders |
| C. | smooth, concentric commutator properly undercut |
| D. | all of the above |
| Answer» D. all of the above | |
| 261. |
Fleming's right-hand rule regarding direction of induced e.m.f., correlates |
| A. | magnetic flux, direction of current flow and resultant force |
| B. | magnetic flux, direction of motion and the direction of e.m.f. induced |
| C. | magnetic field strength, induced voltage and current |
| D. | magnetic flux, direction of force and direction of motion of conductor |
| Answer» B. magnetic flux, direction of motion and the direction of e.m.f. induced | |
| 262. |
While applying Fleming's right-hand rule to And the direction of induced e.m.f., the thumb points towards |
| A. | direction of induced e.m.f. |
| B. | direction of flux |
| C. | direction of motion of the conductor if forefinger points in the direction of generated e.m.f. |
| D. | direction of motion of conductor, if forefinger points along the lines of flux |
| Answer» D. direction of motion of conductor, if forefinger points along the lines of flux | |
| 263. |
The bearings used to support the rotor shafts are generally |
| A. | ball bearings |
| B. | bush bearings |
| C. | magnetic bearmgs |
| D. | needle bearings |
| Answer» A. ball bearings | |
| 264. |
In D.C. generators, the cause of rapid brush wear may be |
| A. | severe sparking |
| B. | rough commutator surface |
| C. | imperfect contact |
| D. | any of the above |
| Answer» D. any of the above | |
| 265. |
In lap winding, the number of brushes is always |
| A. | double the number of poles |
| B. | same as the number of poles |
| C. | half the number of poles |
| D. | two |
| Answer» B. same as the number of poles | |
| 266. |
For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ? |
| A. | Lap winding |
| B. | Wave winding |
| C. | Either of (a) and (b) above |
| D. | Depends on other features of design |
| Answer» B. Wave winding | |
| 267. |
In a four-pole D.C. machine |
| A. | all the four poles are north poles |
| B. | alternate poles are north and south |
| C. | all the four poles are south poles |
| D. | two north poles follow two south poles |
| Answer» B. alternate poles are north and south | |
| 268. |
Copper brushes in D.C. machine are used |
| A. | where low voltage and high currents are involved |
| B. | where high voltage and small cur-rents are involved |
| C. | in both of the above cases |
| D. | in none of the above cases |
| Answer» A. where low voltage and high currents are involved | |
| 269. |
A separately excited generator as compared to a self-excited generator |
| A. | is amenable to better voltage con-trol |
| B. | is more stable |
| C. | has exciting current independent of load current |
| D. | has all above features |
| Answer» D. has all above features | |
| 270. |
In case of D.C. machines, mechanical losses are primary function of |
| A. | current |
| B. | voltage |
| C. | speed |
| D. | none of above |
| Answer» C. speed | |
| 271. |
Iron losses in a D.C. machine are independent of variations in |
| A. | speed |
| B. | load |
| C. | voltage |
| D. | speed and voltage |
| Answer» B. load | |
| 272. |
In D.C. generators, current to the external circuit from armature is given through |
| A. | commutator |
| B. | solid connection |
| C. | slip rings |
| D. | none of above |
| Answer» A. commutator | |
| 273. |
Brushes of D.C. machines are made of |
| A. | carbon |
| B. | soft copper |
| C. | hard copper |
| D. | all of above |
| Answer» A. carbon | |
| 274. |
If B is the flux density, I the length of conductor and v the velocity of conductor, then induced e.m.f. is given by |
| A. | Blv |
| B. | Blv2 |
| C. | Bl2v |
| D. | Bl2v2 |
| Answer» A. Blv | |
| 275. |
In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be |
| A. | 4 |
| B. | 8 |
| C. | 16 |
| D. | 32 |
| Answer» B. 8 | |
| 276. |
The material for commutator brushes is generally |
| A. | mica |
| B. | copper |
| C. | cast iron |
| D. | carbon |
| Answer» D. carbon | |
| 277. |
The insulating material used between the commutator segments is normally |
| A. | graphite |
| B. | paper |
| C. | mica |
| D. | insulating varnish |
| Answer» C. mica | |
| 278. |
In D.C. generators, the brushes on commutator remain in contact with conductors which |
| A. | lie under south pole |
| B. | lie under north pole |
| C. | lie under interpolar region |
| D. | are farthest from the poles |
| Answer» C. lie under interpolar region | |
| 279. |
If brushes of a D.C. generator are moved in order to bring these brushes in magnetic neutral axis, there will be |
| A. | demagnetisation only |
| B. | cross magnetisation as well as magnetisation |
| C. | crossmagnetisation as well as demagnetising |
| D. | cross magnetisation only |
| Answer» C. crossmagnetisation as well as demagnetising | |
| 280. |
Armature reaction of an unsaturated D.C. machine is |
| A. | crossmagnetising |
| B. | demagnetising |
| C. | magnetising |
| D. | none of above |
| Answer» A. crossmagnetising | |
| 281. |
D.C. generators are connected to the busbars or disconnected from them only under the floating condition |
| A. | to avoid sudden loading of the primemover |
| B. | to avoid mechanicaljerk to the shaft |
| C. | to avoid burning of switch contacts |
| D. | all above |
| Answer» D. all above | |
| 282. |
Eddy currents are induced in the pole shoes of a D.C. machine due to |
| A. | oscillating magnetic field |
| B. | pulsating magnetic flux |
| C. | relative rotation between field and armature |
| D. | all above |
| Answer» C. relative rotation between field and armature | |
| 283. |
Equilizer rings are required in case armature is |
| A. | wave wound |
| B. | lap wound |
| C. | delta wound |
| D. | duplex wound |
| Answer» B. lap wound | |
| 284. |
Welding generator will have |
| A. | lap winding |
| B. | wave winding |
| C. | delta winding |
| D. | duplex wave winding |
| Answer» A. lap winding | |
| 285. |
In case of D.C. machine winding, number of commutator segments is equal to |
| A. | number of armature coils |
| B. | number of armature coil sides |
| C. | number of armature conductors |
| D. | number of armature turns |
| Answer» A. number of armature coils | |
| 286. |
For a D.C. machines laboratory following type of D.C. supply will be suitable |
| A. | rotary converter |
| B. | mercury are rectifier |
| C. | induction motor D.C. generator set |
| D. | synchronous motor D.C. generator set |
| Answer» C. induction motor D.C. generator set | |
| 287. |
The function of pole shoes in the case of D.C. machine is |
| A. | to reduce the reluctance of the magnetic path |
| B. | to spread out the flux to achieve uniform flux density |
| C. | to support the field coil |
| D. | to discharge all the above functions |
| Answer» D. to discharge all the above functions | |
| 288. |
In the case of lap winding resultant pitch is |
| A. | multiplication of front and back pitches |
| B. | division of front pitch by back pitch |
| C. | sum of front and back pitches |
| D. | difference of front and back pitches |
| Answer» D. difference of front and back pitches | |
| 289. |
A D.C. welding generator has |
| A. | lap winding |
| B. | wave moving |
| C. | duplex winding |
| D. | any of the above |
| Answer» A. lap winding | |
| 290. |
Which of the following statement about D.C. generators is false ? |
| A. | Compensating winding in a D.C. machine helps in commutation |
| B. | In a D. C. generator interpoles winding is connected in series with the armature winding |
| C. | Back pitch and front pitch are both odd and approximately equal to the pole pitch |
| D. | Equilizing bus bars are used with parallel running of D.C. shunt generators |
| Answer» D. Equilizing bus bars are used with parallel running of D.C. shunt generators | |
| 291. |
The demagnetising component of armature reaction in a D.C. generator |
| A. | reduces generator e.m.f. |
| B. | increases armature speed |
| C. | reduces interpoles flux density |
| D. | results in sparking trouble |
| Answer» A. reduces generator e.m.f. | |
| 292. |
Magnetic field in a D.C. generator is produced by |
| A. | electromagnets |
| B. | permanent magnets |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» A. electromagnets | |
| 293. |
The number of brushes in a commutator depends on |
| A. | speed of armature |
| B. | type of winding |
| C. | voltage |
| D. | amount of current to be collected |
| Answer» D. amount of current to be collected | |
| 294. |
Compensating windings are used in D.C. generators |
| A. | mainly to reduce the eddy currents by providing local short-circuits |
| B. | to provide path for the circulation of cooling air |
| C. | to neutralise the cross-magnetising effect of the armature reaction |
| D. | none of the above |
| Answer» C. to neutralise the cross-magnetising effect of the armature reaction | |
| 295. |
Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator ? |
| A. | Dummy coils |
| B. | Commutator |
| C. | Eye bolt |
| D. | Equilizer rings |
| Answer» B. Commutator | |
| 296. |
In a D.C. generator the ripples in the direct e.m.f. generated are reduced by |
| A. | using conductor of annealed copper |
| B. | using commutator with large number of segments |
| C. | using carbon brushes of superior quality |
| D. | using equiliser rings |
| Answer» C. using carbon brushes of superior quality | |
| 297. |
In D.C. generators, lap winding is used for |
| A. | high voltage, high current |
| B. | low voltage, high current |
| C. | high voltage, low current |
| D. | low voltage, low current |
| Answer» B. low voltage, high current | |
| 298. |
Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generatorA and B will be |
| A. | 2 : 3 |
| B. | 3 : 1 |
| C. | 3 : 2 |
| D. | 1 :3 |
| Answer» B. 3 : 1 | |
| 299. |
The voltage drop for which of the following types of brush can be expected to be least? |
| A. | Graphite brushes |
| B. | Carbon brushes |
| C. | Metal graphite brushes |
| D. | None of the above |
| Answer» C. Metal graphite brushes | |
| 300. |
The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be |
| A. | E/2 |
| B. | 2E |
| C. | slightly less than E |
| D. | E |
| Answer» B. 2E | |
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