McqMate
Chapters
| 101. |
A transformer can have regulation closer to zero |
| A. | on full-load |
| B. | on overload |
| C. | on leading power factor |
| D. | on zero power factor |
| Answer» C. on leading power factor | |
| 102. |
A transformer transforms |
| A. | voltage |
| B. | current |
| C. | current and voltage |
| D. | power |
| Answer» D. power | |
| 103. |
Which of the following is not the standard voltage for power supply in India ? |
| A. | llkV |
| B. | 33kV |
| C. | 66 kV |
| D. | 122 kV |
| Answer» D. 122 kV | |
| 104. |
Reduction in core losses and increase in permeability are obtained with transformer employing |
| A. | core built-up of laminations of cold rolled grain oriented steel |
| B. | core built-up of laminations of hot rolled sheet |
| C. | either of the above |
| D. | none of the above |
| Answer» A. core built-up of laminations of cold rolled grain oriented steel | |
| 105. |
In a power or distribution transformer about 10 per cent end turns are heavily insulated |
| A. | to withstand the high voltage drop due to line surge produced by the shunting capacitance of the end turns |
| B. | to absorb the line surge voltage and save the winding of transformer fromdamage |
| C. | to reflect the line surge and save the winding of a transformer from damage |
| D. | none of the above |
| Answer» A. to withstand the high voltage drop due to line surge produced by the shunting capacitance of the end turns | |
| 106. |
For given applied voltage, with the increase in frequency of the applied voltage |
| A. | eddy current loss will decrease |
| B. | eddy current loss will increase |
| C. | eddy current loss will remain unchanged |
| D. | none of the above |
| Answer» C. eddy current loss will remain unchanged | |
| 107. |
Losses which occur in rotating electric machines and do not occur in transformers are |
| A. | friction and windage losses |
| B. | magnetic losses |
| C. | hysteresis and eddy current losses |
| D. | copper losses |
| Answer» A. friction and windage losses | |
| 108. |
In a given transformer for a given applied voltage, losses which remainconstant irrespective of load changes are |
| A. | hysteresis and eddy current losses |
| B. | friction and windage losses |
| C. | copper losses |
| D. | none of the above |
| Answer» A. hysteresis and eddy current losses | |
| 109. |
Which of the following statements regarding an idel single-phase transformerhaving a turn ratio of 1 : 2 and drawing a current of 10 A from 200 V A.C. supply is incorrect ? |
| A. | Its secondary current is 5 A |
| B. | Its secondary voltage is 400 V |
| C. | Its rating is 2 kVA |
| D. | Its secondary current is 20 A |
| Answer» D. Its secondary current is 20 A | |
| 110. |
The secondary of a current transformer is always short-circuited underoperating conditions because it |
| A. | avoids core saturation and high voltage induction |
| B. | is safe to human beings |
| C. | protects the primary circuit |
| D. | none of the above |
| Answer» A. avoids core saturation and high voltage induction | |
| 111. |
In a transformer the resistance between its primary and secondary should be |
| A. | zero |
| B. | 10 Q |
| C. | 1000 Q |
| D. | infinity |
| Answer» D. infinity | |
| 112. |
A good voltage regulation of a transformer means |
| A. | output voltage fluctuation from no load to full load is least |
| B. | output voltage fluctuation with power factor is least |
| C. | difference between primary and secondary voltage is least |
| D. | difference between primary and secondary voltage ismaximum |
| Answer» A. output voltage fluctuation from no load to full load is least | |
| 113. |
For a transformer, operating at constant load current, maximum efficiency will occur at |
| A. | 0.8 leading power factor |
| B. | 0.8 lagging power factor |
| C. | zero power factor |
| D. | unity power factor |
| Answer» D. unity power factor | |
| 114. |
Which of the following protection is normally not provided on smalldistribution transformers ? |
| A. | Overfluxing protection |
| B. | Buchholz relay |
| C. | Overcurrent protection |
| D. | All of the above |
| Answer» B. Buchholz relay | |
| 115. |
Which of the following acts as a protection against high voltage surges due to lightning and switching ? |
| A. | Horn gaps |
| B. | Thermal overload relays |
| C. | Breather |
| D. | Conservator |
| Answer» A. Horn gaps | |
| 116. |
The efficiency of two identical transformers under load conditionscan be determined by |
| A. | short-circuit test |
| B. | back-to-back test |
| C. | open circuit test |
| D. | any of the above |
| Answer» B. back-to-back test | |
| 117. |
Which of the following insulating materials can withstand the highest temperature safely ? |
| A. | Cellulose |
| B. | Asbestos |
| C. | Mica |
| D. | Glass fibre |
| Answer» C. Mica | |
| 118. |
Which of the following parts of a transformer is visible from outside ? |
| A. | Bushings |
| B. | Core |
| C. | Primary winding |
| D. | Secondary winding |
| Answer» A. Bushings | |
| 119. |
The noise produced by a transformer is termed as |
| A. | zoom |
| B. | hum |
| C. | ringing |
| D. | buzz |
| Answer» B. hum | |
| 120. |
Which of the following loss in a transformer is zero even at full load ? |
| A. | Core loss |
| B. | Friction loss |
| C. | Eddy current loss |
| D. | Hysteresis loss |
| Answer» B. Friction loss | |
| 121. |
Which of the following is the most likely source of harmonics in a transformer ? |
| A. | poor insulation |
| B. | Overload |
| C. | loose connections |
| D. | Core saturation |
| Answer» D. Core saturation | |
| 122. |
If a transformer is continuously operated the maximum temperature rise will occur in |
| A. | core |
| B. | windings |
| C. | tank |
| D. | any of the above |
| Answer» B. windings | |
| 123. |
The hum in a transformer is mainly attributed to |
| A. | load changes |
| B. | oil in the transformer |
| C. | magnetostriction |
| D. | mechanical vibrations |
| Answer» C. magnetostriction | |
| 124. |
The maximum load that a power transformer can carry is limited by its |
| A. | temperature rise |
| B. | dielectric strength of oil |
| C. | voltage ratio |
| D. | copper loss |
| Answer» C. voltage ratio | |
| 125. |
The efficiency of a transformer, under heavy loads, is comparatively low because |
| A. | copper loss becomes high in proportion to the output |
| B. | iron loss is increased considerably |
| C. | voltage drop both in primary and secondary becomes large |
| D. | secondary output is much less as compared to primary input |
| Answer» A. copper loss becomes high in proportion to the output | |
| 126. |
An open-circuit test on a transformer is conducted primarily to measure |
| A. | insulation resistance |
| B. | copper loss |
| C. | core loss |
| D. | total loss |
| Answer» C. core loss | |
| 127. |
A no-load test is performed on a transformer to determine |
| A. | core loss |
| B. | copper loss |
| C. | efficiency |
| D. | magnetising current and loss |
| Answer» D. magnetising current and loss | |
| 128. |
The voltage transformation ratio of a transformer is equal to the ratio of |
| A. | primary turns to secondary turns |
| B. | secondary current to primary current |
| C. | secondary induced e.m.f. to primary induced e.m.f. |
| D. | secondary terminal voltage to primary applied voltage |
| Answer» C. secondary induced e.m.f. to primary induced e.m.f. | |
| 129. |
Part of the transformer which is most subject to damage from overheating is |
| A. | iron core |
| B. | copper winding |
| C. | winding insulation |
| D. | frame or case |
| Answer» C. winding insulation | |
| 130. |
If a transformer is switched on to a voltage more than the rated voltage |
| A. | its power factor will deteriorate |
| B. | its power factor will increase |
| C. | its power factor will remain unaffected |
| D. | its power factor will be zero |
| Answer» A. its power factor will deteriorate | |
| 131. |
Auto-transformer makes effective saving on copper and copper losses, whenits transformation ratio is |
| A. | approximately equal to one |
| B. | less than one |
| C. | great than one |
| D. | none of the above |
| Answer» A. approximately equal to one | |
| 132. |
Minimum voltage regulation occurs when the power factor of the load is |
| A. | unity |
| B. | lagging |
| C. | leading |
| D. | zero |
| Answer» C. leading | |
| 133. |
In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of |
| A. | less than 15 A |
| B. | more than 15 A |
| C. | 15 A |
| D. | none of the above |
| Answer» A. less than 15 A | |
| 134. |
No-load speed of which of the following motor will be highest ? |
| A. | Shunt motor |
| B. | Series motor |
| C. | Cumulative compound motor |
| D. | Differentiate compound motor |
| Answer» B. Series motor | |
| 135. |
The direction of rotation of a D.C. series motor can be changed by |
| A. | interchanging supply terminals |
| B. | interchanging field terminals |
| C. | either of (a) and (b) above |
| D. | None of the above |
| Answer» B. interchanging field terminals | |
| 136. |
Which of the following application requires high starting torque ? |
| A. | Lathe machine |
| B. | Centrifugal pump |
| C. | Locomotive |
| D. | Air blower |
| Answer» C. Locomotive | |
| 137. |
If a D.C. motor is to be selected for conveyors, which rriotor would be preferred ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Differentially compound motor |
| D. | Cumulative compound motor |
| Answer» A. Series motor | |
| 138. |
Which D.C. motor will be preferred for machine tools ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulative compound motor |
| D. | Differential compound motor |
| Answer» B. Shunt motor | |
| 139. |
Differentially compound D.C. motors can find applicationsrequiring |
| A. | high starting torque |
| B. | low starting torque |
| C. | variable speed |
| D. | frequent on-off cycles |
| Answer» B. low starting torque | |
| 140. |
Which D.C. motor is preferred for elevators ? |
| A. | Shunt motor |
| B. | Series motor |
| C. | Differential compound motor |
| D. | Cumulative compound motor |
| Answer» D. Cumulative compound motor | |
| 141. |
If the field of a D.C. shunt motor gets opened while motor is running |
| A. | the speed of motor will be reduced % |
| B. | the armature current will reduce |
| C. | the motor will attain dangerously high speed 1 |
| D. | the motor will continue to nuvat constantspeed |
| Answer» C. the motor will attain dangerously high speed 1 | |
| 142. |
Starters are used with D.C. motors because |
| A. | these motors have high starting torque |
| B. | these motors are not self-starting |
| C. | back e.m.f. of these motors is zero initially |
| D. | to restrict armature current as there is no back e.m.f. whilestarting |
| Answer» D. to restrict armature current as there is no back e.m.f. whilestarting | |
| 143. |
In D.C. shunt motors as load is reduced |
| A. | the speed will increase abruptly |
| B. | the speed will increase in proportion to reduction in load |
| C. | the speed will remain almost/constant |
| D. | the speed will reduce |
| Answer» C. the speed will remain almost/constant | |
| 144. |
A D.C. series motor is that which |
| A. | has its field winding consisting of thick wire and lessturns |
| B. | has a poor torque |
| C. | can be started easily without load |
| D. | has almost constant speed |
| Answer» A. has its field winding consisting of thick wire and lessturns | |
| 145. |
For starting a D.C. motor a starter is required because |
| A. | it limits the speed of the motor |
| B. | it limits the starting current to a safe value |
| C. | it starts the motor |
| D. | none of the above |
| Answer» B. it limits the starting current to a safe value | |
| 146. |
The type of D.C. motor used for shears and punches is |
| A. | shunt motor |
| B. | series motor |
| C. | differential compoutid D.C. motor |
| D. | cumulative compound D.C. motor |
| Answer» D. cumulative compound D.C. motor | |
| 147. |
If a D.C. motor is connected across the A.C. supply it will |
| A. | run at normal speed |
| B. | not run |
| C. | run at lower speed |
| D. | burn due to heat produced in the field winding by .eddy currents |
| Answer» D. burn due to heat produced in the field winding by .eddy currents | |
| 148. |
To get the speed of D.C, motor below the normal without wastage of electrical energy is used. |
| A. | Ward Leonard control |
| B. | rheostatic control |
| C. | any of the above method |
| D. | none of the above method |
| Answer» A. Ward Leonard control | |
| 149. |
When two D.C. series motors are connected in parallel, the resultant speed is |
| A. | more than the normal speed |
| B. | loss than the normal speed |
| C. | normal speed |
| D. | zero |
| Answer» C. normal speed | |
| 150. |
The speed of a D.C. shunt motor more than its full-load speed can be obtained by |
| A. | decreasing the field current |
| B. | increasing the field current |
| C. | decreasing the armature current |
| D. | increasing the armature current |
| Answer» A. decreasing the field current | |
| 151. |
In a D.C. shunt motor, speed is |
| A. | independent of armature current |
| B. | directly proportional to the armature current |
| C. | proportional to the square of the current |
| D. | inversely proportional to the armature current |
| Answer» A. independent of armature current | |
| 152. |
A direct on line starter is used: for starting motors |
| A. | iip to 5 H.P. |
| B. | up to 10 H.P. |
| C. | up to 15 H.P. |
| D. | up to 20 H.P. |
| Answer» A. iip to 5 H.P. | |
| 153. |
What will happen if the back e.m.f. of a D.C. motor vanishes suddenly? |
| A. | The motor will stop |
| B. | The motor will continue to run |
| C. | The armature may burn |
| D. | The motor will run noisy |
| Answer» C. The armature may burn | |
| 154. |
In case of D.C. shunt motors the speed is dependent on back e.m.f. only because |
| A. | back e.m.f. is equal to armature drop |
| B. | armature drop is negligible |
| C. | flux is proportional to armature current |
| D. | flux is practically constant in D:C. shuntmotors |
| Answer» D. flux is practically constant in D:C. shuntmotors | |
| 155. |
In a D.C. shunt motor, under the conditions of maximum power, the current inthe armature will be |
| A. | almost negligible |
| B. | rated full-load current |
| C. | less than full-load current |
| D. | more than full-load current |
| Answer» D. more than full-load current | |
| 156. |
These days D.C. motors are widely used in |
| A. | pumping sets |
| B. | air compressors |
| C. | electric traction |
| D. | machine shops |
| Answer» C. electric traction | |
| 157. |
By looking at which part of the motor, it can be easily confirmedthat a particular motor is D.C. motor? |
| A. | Frame |
| B. | Shaft |
| C. | Commutator |
| D. | Stator |
| Answer» C. Commutator | |
| 158. |
In which of the following applications D.C. series motor is invariably tried? |
| A. | Starter for a car |
| B. | Drive for a water pump |
| C. | Fan motor |
| D. | Motor operation in A.C. or D.C. |
| Answer» A. Starter for a car | |
| 159. |
In D.C. machines fractional pitch winding is used |
| A. | to improve cooling |
| B. | to reduce copper losses |
| C. | to increase the generated e.m.f. |
| D. | to reduce the sparking |
| Answer» D. to reduce the sparking | |
| 160. |
A three point starter is considered suitable for |
| A. | shunt motors |
| B. | shunt as well as compound motors |
| C. | shunt, compound and series motors |
| D. | all D.C. motors |
| Answer» B. shunt as well as compound motors | |
| 161. |
In case-the conditions for maximum power for a D.C. motor are established,the efficiency of the motor will be |
| A. | 100% |
| B. | around 90% |
| C. | anywhere between 75% and 90% |
| D. | less than 50% |
| Answer» D. less than 50% | |
| 162. |
The ratio of starting torque to full-load torque is least in case of |
| A. | series motors |
| B. | shunt motors |
| C. | compound motors |
| D. | none of the above |
| Answer» B. shunt motors | |
| 163. |
In D.C. motor which of the following can sustain the maximum temperature rise? |
| A. | Slip rings |
| B. | Commutator |
| C. | Field winding |
| D. | Armature winding |
| Answer» C. Field winding | |
| 164. |
Which of the following law/rule can he used to determine the direction of rotationof D.C. motor ? |
| A. | Lenz's law |
| B. | Faraday's law |
| C. | Coloumb'slaw |
| D. | Fleming's left-hand rule |
| Answer» D. Fleming's left-hand rule | |
| 165. |
Which of the following load normally needs starting torque more than therated torque? |
| A. | Blowers |
| B. | Conveyors |
| C. | Air compressors |
| D. | Centrifugal pumps |
| Answer» B. Conveyors | |
| 166. |
The starting resistance of a D.C. motor is generally |
| A. | low |
| B. | around 500 Q |
| C. | 1000 Q |
| D. | infinitely large |
| Answer» A. low | |
| 167. |
The speed of a D.C. series motor is |
| A. | proportional to the armature current |
| B. | proportional to the square of the armature current |
| C. | proportional to field current |
| D. | inversely proportional to the armature current |
| Answer» D. inversely proportional to the armature current | |
| 168. |
In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to |
| A. | 100% of the previous value |
| B. | 50% of the previous value |
| C. | 25% of the previous value |
| D. | 10% of the previous value |
| Answer» C. 25% of the previous value | |
| 169. |
The current drawn by the armature of D.C. motor is directly proportional to |
| A. | the torque required |
| B. | the speed of the motor |
| C. | the voltage across the terminals |
| D. | none of the above |
| Answer» A. the torque required | |
| 170. |
The power mentioned on the name plate of an electric motor indicates |
| A. | the power drawn in kW |
| B. | the power drawn in kVA |
| C. | the gross power |
| D. | the output power available at the shaft |
| Answer» D. the output power available at the shaft | |
| 171. |
Which D.C. motor has got maximum self loading property? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded 'motor |
| D. | Differentially compounded motor |
| Answer» D. Differentially compounded motor | |
| 172. |
Which D.C. motor will be suitable alongwith flywheel for intermittent light andheavy loads? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor |
| Answer» C. Cumulatively compounded motor | |
| 173. |
If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens |
| A. | nothing will happen to th£ motor |
| B. | this will make armature to take heavy current, possibly burning it |
| C. | this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses |
| D. | motor will run at very slow speed |
| Answer» C. this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses | |
| 174. |
D.C. series motors are used |
| A. | where load is constant |
| B. | where load changes frequently |
| C. | where constant operating speed is needed |
| D. | in none of the above situations. |
| Answer» D. in none of the above situations. | |
| 175. |
For the same H.P. rating and full load speed, following motor has poor starting torque |
| A. | shunt |
| B. | series |
| C. | differentially compounded |
| D. | cumulativelyc'ompounded |
| Answer» C. differentially compounded | |
| 176. |
In case of conductively compensated D.C. series motors, the compensating winding is provided |
| A. | as separately wound unit |
| B. | in parallel with armature winding |
| C. | in series with armature winding |
| D. | in parallel with field winding |
| Answer» C. in series with armature winding | |
| 177. |
Sparking at the commutator of a D.C. motor may result in |
| A. | damage to commutator segments |
| B. | damage to commutator insulation |
| C. | increased power consumption |
| D. | all of the above |
| Answer» D. all of the above | |
| 178. |
Which of the following motor is preferred for operation in highly explosive atmosphere ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Air motor |
| D. | Battery operated motor |
| Answer» C. Air motor | |
| 179. |
If the supply voltage for a D.C. motor is increased, which of the following willdecrease ? |
| A. | Starting torque |
| B. | Operating speed |
| C. | Full-load current |
| D. | All of the above |
| Answer» C. Full-load current | |
| 180. |
Which one of the following is not the function of pole shoes in a D.C. machine ? |
| A. | To reduce eddy current loss |
| B. | To support the field coils |
| C. | To spread out flux for better unifor-mity |
| D. | To reduce the reluctance of the mag-netic path |
| Answer» A. To reduce eddy current loss | |
| 181. |
The mechanical power developed by a shunt motor will be maximum when theratio of back e.m.f. to applied voltage is |
| A. | 4.0 |
| B. | 2.0 |
| C. | 1.0 |
| D. | 0.5 |
| Answer» D. 0.5 | |
| 182. |
For which of the following applications a D.C. motor is preferred over an A.C. motor? |
| A. | Low speed operation |
| B. | High speed operation |
| C. | Variable speed operation |
| D. | Fixed speed operation |
| Answer» C. Variable speed operation | |
| 183. |
In D.C. machines the residual magnetism is of the order of |
| A. | 2 to 3 per cent |
| B. | 10 to 15 per cent |
| C. | 20 to 25 per cent |
| D. | 50 to 75 per cent |
| Answer» A. 2 to 3 per cent | |
| 184. |
Which D.C. motor is generally preferred for cranes and hoists ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor |
| Answer» A. Series motor | |
| 185. |
Three point starter can be used for |
| A. | series motor only |
| B. | shunt motor only |
| C. | compound motor only |
| D. | both shunt and compound motor |
| Answer» D. both shunt and compound motor | |
| 186. |
Sparking, is discouraged in a D.C. motor because |
| A. | it increases the input power con-sumption |
| B. | commutator gets damaged |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» B. commutator gets damaged | |
| 187. |
Speed control by Ward Leonard method gives uniform speed variation |
| A. | in one direction |
| B. | in both directions |
| C. | below normal speed only |
| D. | above normal speed only. |
| Answer» B. in both directions | |
| 188. |
Flywheel is used with D.C. compound motor to reduce the peak demand by the motor, compound motor will have to be |
| A. | level compounded |
| B. | under compounded |
| C. | cumulatively compounded |
| D. | differentially compounded |
| Answer» C. cumulatively compounded | |
| 189. |
Following motor is used where high starting torque and wide speed range control is required. |
| A. | Single phase capacitor start |
| B. | Induction motor |
| C. | Synchronous motor |
| D. | D.C. motor |
| Answer» D. D.C. motor | |
| 190. |
In a differentially compounded D.C. motor, if shunt field suddenly opens |
| A. | the motor will first stop and then run in opposite direction as series motor |
| B. | the motor will work as series motor and run at slow speed in the same direction |
| C. | the motor will work as series motor and run at high speed in the samedirection |
| D. | the motor will not work and come to stop |
| Answer» A. the motor will first stop and then run in opposite direction as series motor | |
| 191. |
Which of the following motor has the poorest speed regulation ? |
| A. | Shunt motor |
| B. | Series motor |
| C. | Differential compound motor |
| D. | Cumulative compound motor |
| Answer» B. Series motor | |
| 192. |
Buses, trains, trolleys, hoists, cranes require high starting torque and therefore make use of |
| A. | D.C. series motor |
| B. | D.C. shunt motor |
| C. | induction motor |
| D. | all of above motors |
| Answer» A. D.C. series motor | |
| 193. |
As -the load is increased the speed of D.C. shunt motor will |
| A. | reduce slightly |
| B. | increase slightly |
| C. | increase proportionately |
| D. | remains unchanged |
| Answer» A. reduce slightly | |
| 194. |
The armature torque of the D.C. shunt motor is proportional to |
| A. | field flux only |
| B. | armature current only |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» B. armature current only | |
| 195. |
Which of the following method of speed control of D.C. machine will offer minimum efficiency ? |
| A. | Voltage control method |
| B. | Field control method |
| C. | Armature control method |
| D. | All above methods |
| Answer» C. Armature control method | |
| 196. |
Usually wide and sensitive speed control is desired in case of |
| A. | centrifugal pumps |
| B. | elevators |
| C. | steel rolling mills |
| D. | colliery winders |
| Answer» D. colliery winders | |
| 197. |
The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load.The speed regulation of the motor is |
| A. | 2.36% |
| B. | 4.76% |
| C. | 6.77% |
| D. | 8.84% |
| Answer» B. 4.76% | |
| 198. |
The armature voltage control of D.C. motor provides |
| A. | constant torque drive |
| B. | constant voltage drive |
| C. | constant current drive |
| D. | none of the above |
| Answer» A. constant torque drive | |
| 199. |
As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit |
| A. | a resistance is connected in series with armature |
| B. | a resistance is connected parallel to the armature |
| C. | armature is temporarily open circuited |
| D. | a high value resistor is connected across the fieldwinding |
| Answer» A. a resistance is connected in series with armature | |
| 200. |
The speed of a D.C. shunt motor can be increased by |
| A. | increasing the resistance in armature circuit |
| B. | increasing the resistance in field circuit |
| C. | reducing the resistance in the field circuit |
| D. | reducing the resistance in the armature circuit |
| Answer» B. increasing the resistance in field circuit | |
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