MCQOPTIONS
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MCQOPTIONS
This section includes 198 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The common impurity in the electrolyte of lead-acid battery is? |
| A. | chlorine |
| B. | dust particles |
| C. | lead crystals |
| D. | iron |
| Answer» E. | |
| 152. |
During charging the specific gravity of the electrolyte of a lead-acid battery? |
| A. | increases |
| B. | decreases |
| C. | remains the same |
| D. | becomes zero |
| Answer» B. decreases | |
| 153. |
Hydrogen evolved during charging produces explosive mixture when it is more than? |
| A. | 2% |
| B. | 4% |
| C. | 6% |
| D. | 8% |
| Answer» E. | |
| 154. |
Life of the batteries is in the following ascending order. |
| A. | Lead-acid cell, Edison cell, Nickel cadmium cell |
| B. | Lead-acid cell, Nickel-cadmium cell, Edison cell |
| C. | Edison cell, Nickel-cadmium cell, lead-acid cell |
| D. | Nickel-cadmium cell, Edison cell, lead-acid cell |
| Answer» B. Lead-acid cell, Nickel-cadmium cell, Edison cell | |
| 155. |
Petroleum jelly is applied to the electrical connections to the lead-acid battery |
| A. | prevent local heating |
| B. | prevent short-circuiting |
| C. | reduce path resistance |
| D. | prevent corrosion |
| Answer» E. | |
| 156. |
During the charging and discharging of a nickel-iron cell |
| A. | corrosive fumes are produced |
| B. | water is neither formed nor absorbed |
| C. | nickel hydroxide remains unsplit |
| D. | its e.m.f. remains constant |
| Answer» C. nickel hydroxide remains unsplit | |
| 157. |
On the average the ampere-hour efficiency of an Edison cell is about |
| A. | 40% |
| B. | 60% |
| C. | 70% |
| D. | 80% |
| Answer» E. | |
| 158. |
The best indication about the state of charge on a lead-acid battery is given by |
| A. | output voltage |
| B. | temperature of electrolyte |
| C. | specific gravity of electrolyte |
| D. | none of the above |
| Answer» D. none of the above | |
| 159. |
The active materials of a nickel-iron battery are |
| A. | nickel hydroxide |
| B. | powdered iron and its oxide |
| C. | 21% solution of kOH |
| D. | all of the above |
| Answer» E. | |
| 160. |
The open circuit voltage of any storage cell depends wholly upon |
| A. | its chemical constituents |
| B. | on the strength of its electrolyte |
| C. | its temperature |
| D. | all above |
| Answer» E. | |
| 161. |
Which of the following has lower sp. gravity V |
| A. | Dilute H‚ÇÇSO‚ÇÑ |
| B. | Concentrated H‚ÇÇSO‚ÇÑ |
| C. | Water |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 162. |
The average charging voltage for alkali cell is about |
| A. | 1 V |
| B. | 1.2 V |
| C. | 1.7 V |
| D. | 2.1 V |
| Answer» D. 2.1 V | |
| 163. |
In a lead-acid cell, if the specific gravity of sulphuric acid is 1.8, it will require following ratio of acid to water to get mixture of specific gravity of 1.3 |
| A. | 6 parts of acid to 4 parts of water |
| B. | 4 parts of acid to 4 parts of water |
| C. | 4 parts of acid to 6 parts of water |
| D. | 4 parts of acid to 8 parts of water |
| Answer» D. 4 parts of acid to 8 parts of water | |
| 164. |
In order that a hydrometer may float vertically in electrolyte its C.G. should be |
| A. | lowered |
| B. | raised |
| C. | undisturbed |
| D. | displaced sideways |
| Answer» B. raised | |
| 165. |
During discharge, the active material of both the positive and negative plates is changed to |
| A. | Pb |
| B. | Pb02 |
| C. | PbO |
| D. | PbS04 |
| Answer» E. | |
| 166. |
Following will happen if the specific gravity of electrolyte becomes more than 1.23. |
| A. | Loss of capacity |
| B. | Loss of life |
| C. | Corrosion of the grids of the plate |
| D. | All above |
| Answer» E. | |
| 167. |
Under normal charging rate, the charging current should be |
| A. | 10% of capacity |
| B. | 20% of capacity |
| C. | 30% of capacity |
| D. | 40% of capacity |
| Answer» B. 20% of capacity | |
| 168. |
When the lead-acid cell is fully charged, the electrolyte assumes _____ appearance |
| A. | dull |
| B. | reddish |
| C. | bright |
| D. | milky |
| Answer» E. | |
| 169. |
Capacity of a battery.is expressed in |
| A. | Ah |
| B. | Vh |
| C. | Wh |
| D. | kWh |
| Answer» B. Vh | |
| 170. |
A typical output of a solar cell is |
| A. | 0.1 V |
| B. | 0.26 V |
| C. | 1.1 V |
| D. | 2 V |
| Answer» C. 1.1 V | |
| 171. |
In a lead-acid cell, lead is called as |
| A. | positive active material |
| B. | negative active material |
| C. | passive material |
| D. | none of the above |
| Answer» C. passive material | |
| 172. |
When the specific gravity of the electrolyte of a lead-acid cell is reduced to 1.1 to 1.15 the cell is in |
| A. | charged state |
| B. | discharged state |
| C. | both (A) and (B) |
| D. | active state |
| Answer» C. both (A) and (B) | |
| 173. |
All the electrical connections between the battery and vehicle should be by |
| A. | thin aluminium wires |
| B. | thin copper wires |
| C. | rigid cables |
| D. | flexible cables |
| Answer» E. | |
| 174. |
Electrolyte used in an Edison cell is |
| A. | NaOH |
| B. | kOH |
| C. | HC1 |
| D. | HN03 |
| Answer» C. HC1 | |
| 175. |
Which of the following primary cells has the highest voltage ? |
| A. | Manganese-alkaline |
| B. | Carbon-zinc |
| C. | Lithium |
| D. | Mercury |
| Answer» D. Mercury | |
| 176. |
The capacity of a lead-acid cell does not depend on its |
| A. | temperature |
| B. | rate of charge |
| C. | rate of discharge |
| D. | quantity of active material |
| Answer» C. rate of discharge | |
| 177. |
Shelf life of a small dry cell is |
| A. | equal to that of large dry cell |
| B. | less than that of large dry cell |
| C. | more than that of large dry cell |
| D. | none of the above |
| Answer» C. more than that of large dry cell | |
| 178. |
The body of Edison cell is made of |
| A. | bakelite |
| B. | rubber |
| C. | nickel plated steel |
| D. | aluminium |
| Answer» D. aluminium | |
| 179. |
Which of the following cell has a reversible chemical reaction ? |
| A. | Lead-acid |
| B. | Mercury oxide |
| C. | Carbon-zinc |
| D. | Silver-oxide |
| Answer» B. Mercury oxide | |
| 180. |
Satellite power requirement is provided through |
| A. | solar cells |
| B. | dry cells |
| C. | nickel-cadmium cells |
| D. | lead-acid batteries |
| Answer» B. dry cells | |
| 181. |
Extent of corrosion in the underground metal work depends upon |
| A. | amount of moisture |
| B. | type of metals |
| C. | type of soil chemicals |
| D. | all above factors |
| Answer» E. | |
| 182. |
The lead-acid cell should never be discharged beyond |
| A. | 1.8 V |
| B. | 1.9 V |
| C. | 2 V |
| D. | 2.1 V |
| Answer» B. 1.9 V | |
| 183. |
Following will occur if level of electrolyte falls below plates |
| A. | capacity of the cell is reduced |
| B. | life of the cell is reduced |
| C. | open plates are converted to lead sulphate |
| D. | all above |
| Answer» E. | |
| 184. |
“The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity”.The above statement is associated with# |
| A. | Newton’s law |
| B. | Faraday’s law of electromagnetic |
| C. | Faraday’s law of electrolysis |
| D. | Gauss’s law |
| Answer» D. Gauss‚Äö√Ñ√¥s law | |
| 185. |
Which of the following battery is used for aircraft ? |
| A. | Lead-acid battery |
| B. | Nickel-iron battery |
| C. | Dry cell battery |
| D. | Silver oxide battery |
| Answer» C. Dry cell battery | |
| 186. |
Trickle charging of a storage battery helps to |
| A. | maintain proper electrolyte level |
| B. | increase its reserve capacity |
| C. | prevent sulphation |
| D. | keep it fresh and fully charged |
| Answer» E. | |
| 187. |
Cell short circuit results in |
| A. | low sp. gravity electrolyte |
| B. | abnormal high temperature |
| C. | reduced gassing on charge |
| D. | all above |
| Answer» E. | |
| 188. |
Level of electrolyte in a cell should be _____ the level of plates |
| A. | below |
| B. | equal to |
| C. | above |
| D. | none of the above |
| Answer» D. none of the above | |
| 189. |
The capacity of a lead-acid cell depends on |
| A. | Rate of discharge |
| B. | Temperature |
| C. | Density of electrolyte |
| D. | All above |
| Answer» E. | |
| 190. |
Life of the Edison cell is at least |
| A. | five years |
| B. | seven years |
| C. | eight years |
| D. | ten years |
| Answer» B. seven years | |
| 191. |
The internal resistance of an alkali cell is nearly _____ times that of the lead-acid cell. |
| A. | two |
| B. | three |
| C. | four |
| D. | five |
| Answer» E. | |
| 192. |
Short circuiting of a cell may be caused |
| A. | buckling of plates |
| B. | faulty separators |
| C. | lead particles forming circuit between positive and negative plates |
| D. | excessive accumulation of sediment |
| E. | any one of above |
| Answer» F. | |
| 193. |
Excessive formation of lead sulphate on the surface of the plates happens because of |
| A. | allowing a battery to stand in discharged condition for a long time |
| B. | topping up with electrolyte |
| C. | persistent undercharging |
| D. | low level of electrolyte |
| E. | all above |
| Answer» F. | |
| 194. |
The internal resistance of a lead-acid cell is that of Edison cell |
| A. | Less than |
| B. | More than |
| C. | Equal to |
| D. | None of the above |
| Answer» B. More than | |
| 195. |
Internal resistance of a cell is reduced by |
| A. | using vent plug to permit gas formed during discharge |
| B. | increasing the plate area |
| C. | putting plates very close together |
| D. | all above methods |
| Answer» E. | |
| 196. |
Self charge of a Ni-Fe cell is _____ Edison cell. |
| A. | Equal to |
| B. | Less than |
| C. | More than |
| D. | Much more than |
| Answer» C. More than | |
| 197. |
It is noticed that durum charging |
| A. | there is a rise in voltage |
| B. | energy is absorbed by the cell |
| C. | specific gravity of H‚ÇÇSO‚ÇÑ is increased |
| D. | the anode becomes chocolate brown in colour (PbCfe) and cathode becomes grey metallic lead (Pb) |
| E. | all of the above |
| Answer» F. | |
| 198. |
For a cell to work, which of the following condition(s) become necessary ? |
| A. | Two electrodes of different meta’s should be inserted in the electrolyte, not touching each other |
| B. | Electrolyte must chemically react with one of the electrodes |
| C. | Electrolyte liquid or paste should be conducting |
| D. | All above three conditions are necessary |
| Answer» E. | |