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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.
101. |
%_The storage battery generally used in electric power station is_% |
A. | nickel-cadmium battery |
B. | zinc-carbon battery |
C. | lead-acid battery |
D. | none of the above |
Answer» D. none of the above | |
102. |
%_Ampere hour capacity of an industrial battery is based on ____ hours discharge rate._% |
A. | 8 |
B. | 12 |
C. | 16 |
D. | 24 |
Answer» B. 12 | |
103. |
%_A constant-voltage generator has_% |
A. | minimum efficiency |
B. | minimum current capacity |
C. | low internal resistance |
D. | high internal resistance |
Answer» D. high internal resistance | |
104. |
%_Those substances of the cell which take active part in chemical combination and hence produce electricity during charging or discharging are known as______materials._% |
A. | passive |
B. | active |
C. | redundant |
D. | inert |
Answer» C. redundant | |
105. |
%_When a lead-acid battery is in fully charged condition, the color of its positive plate is_% |
A. | dark grey |
B. | brown |
C. | dark brown |
D. | none of above |
Answer» D. none of above | |
106. |
%_Specific gravity of electrolyte in Edison cell is_% |
A. | 0.8 |
B. | 0.95 |
C. | 1.1 |
D. | 1.21 |
Answer» E. | |
107. |
_ If a lead-acid cell is discharged below 1.8 V the following will happen.$? |
A. | Capacity of cell will reduce |
B. | Sulphation of plates will occur |
C. | Internal resistance will increase |
D. | All above will occur |
Answer» E. | |
108. |
_ The ratio of ampere-hour efficiency to watt-hour efficiency of a lead-acid cell is$? |
A. | just one |
B. | always greater than one |
C. | always less than one |
D. | none of the above |
Answer» C. always less than one | |
109. |
_ The capacity of a battery is expressed in terms of$? |
A. | current rating |
B. | voltage rating |
C. | ampere-hour rating |
D. | none of the above |
Answer» D. none of the above | |
110. |
_ Following will happen if battery charging rate is too high$? |
A. | excessive gassing will occur |
B. | temperature rise will occur |
C. | bulging and buckling of plates will occur |
D. | all above will occur |
Answer» E. | |
111. |
__Charging a sulphated battery at high rate results in__ |
A. | boiling of electrolyte due to gassing |
B. | warping of plates |
C. | damage to separators, cell caps covers and battery case due to excessive temperature |
D. | all above |
Answer» E. | |
112. |
_________ of electrolyte indicates the state of charge of the battery__ |
A. | colour |
B. | mass |
C. | viscosity |
D. | specific gravity |
Answer» E. | |
113. |
__Batteries are charged by__ |
A. | rectifiers |
B. | engine generator sets |
C. | motor generator sets |
D. | any one of the above methods |
Answer» E. | |
114. |
__The capacity of a lead-acid cell is measured in__ |
A. | amperes |
B. | ampere-hours |
C. | watts |
D. | watt-hours |
Answer» C. watts | |
115. |
__Dry cell is modification of__ |
A. | Deniell cell |
B. | Leclanche cell |
C. | Lead-acid cell |
D. | Edison cell |
Answer» C. Lead-acid cell | |
116. |
__The effect of sulphation is that the internal resistance__ |
A. | increases |
B. | decreases |
C. | remains same |
D. | none of the above |
Answer» B. decreases | |
117. |
__During the charging of a lead-acid cell__ |
A. | its voltage increases |
B. | it gives out energy |
C. | its cathode becomes dark chocolate brown in colour |
D. | specific gravity of H‚ÇÇSO‚ÇÑ decreases |
Answer» B. it gives out energy | |
118. |
__The following indicate that battery on charge has attained full charge__ |
A. | colour of electrode |
B. | gassing |
C. | specific gravity |
D. | all above |
Answer» E. | |
119. |
__Persons preparing electrolyte should wear__ |
A. | goggles or other face shield |
B. | rubber |
C. | rubber boots and gloves |
D. | all above safety devices |
Answer» E. | |
120. |
__The current flow through electrolyte is due to the movement of__ |
A. | ions |
B. | holes |
C. | electrons |
D. | none of the above |
Answer» B. holes | |
121. |
__In constant voltage charging method, the charging current from discharged to fully charged condition__ |
A. | decreases |
B. | increases |
C. | remains constant |
D. | none of the above |
Answer» B. increases | |
122. |
__Internal short circuits are caused by__ |
A. | breakdown of one or more separators |
B. | excess accumulation of sediment at the bottom of the cell |
C. | both (A) and (B) |
D. | none of the above |
Answer» D. none of the above | |
123. |
__When two batteries are connected in parallel, it should be ensured that__ |
A. | they have same e.m.f. |
B. | they have same make |
C. | they have same ampere-hour capacity |
D. | they have identical internal resistance |
Answer» B. they have same make | |
124. |
__If a battery is wrongly connected on charge following will happen__ |
A. | current delivered by the battery will be high |
B. | current drawing will be nil |
C. | current drawing will be very small |
D. | current drawing will be very high |
Answer» E. | |
125. |
__The charge required to liberate one gram equivalent of any substance is known as ______ constant__ |
A. | Time |
B. | Faraday’s |
C. | Boltzman |
D. | none of the above |
Answer» C. Boltzman | |
126. |
__In a lead-acid battery the energy is stored in the form of__ |
A. | charged ions |
B. | chemical energy |
C. | electrostatic energy |
D. | electromagnetic energy |
Answer» C. electrostatic energy | |
127. |
__In a battery cover is placed over the element and sealed to the top of the battery container. This is done__ |
A. | to reduce evaporation of water from electrolyte |
B. | to exclude dirt and foreign matter from the electrolyte |
C. | to discharge both of the above functions |
D. | to discharge none of the above functions |
Answer» D. to discharge none of the above functions | |
128. |
_The substances which combine together to store electrical energy during the charge are called ______ materials$? |
A. | active |
B. | passive |
C. | inert |
D. | dielectric |
Answer» B. passive | |
129. |
_While preparing electrolyte for a lead-acid battery$? |
A. | water is poured into acid |
B. | acid is poured into water |
C. | anyone of the two can be added to other chemical |
D. | none of the above |
Answer» C. anyone of the two can be added to other chemical | |
130. |
_It is noticed that during discharging the following does not happen$? |
A. | both anode and cathode become PbS04 |
B. | specific gravity of H?SO? decreases |
C. | voltage of the cell decreases |
D. | the cell absorbs energy |
Answer» E. | |
131. |
_Mercury cell has which of the following characteristics?$? |
A. | Flat discharge current-voltage curve |
B. | High power to weight ratio |
C. | Comparatively longer shelf life under adverse conditions of high temperature and humidity |
D. | All of the above |
Answer» E. | |
132. |
Five 2 V cells are connected in parallel. The output voltage is$? |
A. | 1 V |
B. | 1.5 V |
C. | 1.75 V |
D. | 2 V |
Answer» E. | |
133. |
Excessive charging a battery tends to$? |
A. | produce gassing |
B. | increase the internal resistance of the battery |
C. | to corrode the positive plates into lead peroxide thereby weakening them physically |
D. | bring about all above changes |
Answer» E. | |
134. |
On overcharging a battery$? |
A. | It will bring about chemical change in active materials |
B. | It will increase the capacity of the battery |
C. | It will raise the specific gravity of the electrolyte |
D. | None of the above will occur |
Answer» E. | |
135. |
Each cell has a vent cap$? |
A. | to allow gases out when the cell is on charge |
B. | to add water to the cell if needed |
C. | to check the level of electrolyte |
D. | to do all above functions |
Answer» E. | |
136. |
As compared to a lead-acid cell, the efficiency of a nickel-iron cell is less due to its$? |
A. | compactness |
B. | lower e.m.f. |
C. | small quantity of electrolyte used |
D. | higher internal resistance |
Answer» E. | |
137. |
Battery charging equipment is generally installed$? |
A. | In well ventilated location |
B. | In clean and dry place |
C. | As near as practical to the battery being charged |
D. | In location having all above features |
Answer» E. | |
138. |
Internal resistance of a cell is due to$? |
A. | resistance of electrolyte |
B. | electrode resistance |
C. | surface contact resistance between electrode and electrolyte |
D. | all above |
Answer» E. | |
139. |
Lead-acid cell has a life of nearly charges and discharges$? |
A. | 500 |
B. | 700 |
C. | 1000 |
D. | 1250 |
Answer» E. | |
140. |
Capacity of dry cells is$? |
A. | more when it is supplying current for intermittent periods |
B. | more when it is supplying current for continuous periods |
C. | unaffected by the type of discharge |
D. | none of the above |
Answer» B. more when it is supplying current for continuous periods | |
141. |
Which of the following factors adversely affects the capacity of the leadacid battery ?$? |
A. | Temperature of surroundings |
B. | Specific gravity of electrolyte |
C. | Rate of discharge |
D. | All of the above |
Answer» E. | |
142. |
During charging the specific gravity of the electrolyte of a lead-acid battery$? |
A. | increases |
B. | decreases |
C. | remains the same |
D. | becomes zero |
Answer» B. decreases | |
143. |
Hydrogen evolved during charging produces explosive mixture when it is more than$? |
A. | 2% |
B. | 4% |
C. | 6% |
D. | 8% |
Answer» E. | |
144. |
Weston standard cell at 20°C has voltage of ____ volts.$? |
A. | 0.8 |
B. | 0.9 |
C. | 1.0187 |
D. | 1.5 |
Answer» D. 1.5 | |
145. |
In a lead-acid cell dilute sulfuric acid (electrolyte) approximately comprises the following$? |
A. | one part H2O, three parts H‚ÇÇSO‚ÇÑ |
B. | two parts H2O, two parts H‚ÇÇSO‚ÇÑ |
C. | three parts H2O, one part H‚ÇÇSO‚ÇÑ |
D. | all H‚ÇÇSO‚ÇÑ |
Answer» D. all H‚Äö√á√áSO‚Äö√á√ë | |
146. |
Battery container should be acid resistance, therefore it is made up of$? |
A. | glass |
B. | plastic |
C. | wood |
D. | all above |
Answer» E. | |
147. |
When the load resistance equals the generator resistance which of the following will be maximum ?$? |
A. | Current |
B. | Efficiency of the circuit |
C. | Power in the load resistance |
D. | Voltage across the load resistance |
Answer» D. Voltage across the load resistance | |
148. |
In ______ system the charging current is intermittently controlled at either a maximum or minimum value$? |
A. | two rate charge control |
B. | trickle charge |
C. | floating charge |
D. | an equalizing charge |
Answer» B. trickle charge | |
149. |
Which of the following primary cells has the lowest voltage ?$? |
A. | Lithium |
B. | Zinc-chloride |
C. | Mercury |
D. | Carbon-zinc |
Answer» D. Carbon-zinc | |
150. |
The output voltage of a charger is$? |
A. | less than the battery voltage |
B. | higher than the battery voltage |
C. | the same as the battery voltage |
D. | none of the above |
Answer» C. the same as the battery voltage | |