electrical engineering Mcqs
1. economics of power generation2. analog electronics3. solid state switching circuits4. parallel circuits5. switchgear and protection6. op amp circuits7. transistor audio power amplifiers8. electrostatics9. heating and welding10. multi stage transistor amplifiers11. passive filters12. network theorems13. regulated d c power supply14. a c fundamentals circuits and circuit theory15. electromagnetic induction16. power electronics17. magnetism and electromagnetism18. transformers19. modulation and demodulation20. d c generators21. semiconductor theory22. single phase induction motors23. semiconductor diode24. hybrid parameters25. digital electronics26. oscillators27. earthing or grounding28. single stage transistor amplifiers29. d c motors30. transistor biasing31. amplifiers with negative feedback32. basic electrical33. electronic instruments34. synchronous motors35. field effect transistors fet36. magnetic circuit37. control systems38. industrial drives39. power generation40. series parallel circuits41. transistor tuned amplifiers42. electrical engineering materials43. rectifiers and converters44. integrated circuits45. scr silicon controlled rectifiers46. cables47. polyphase induction motors48. measurement and instrumentation49. transistors50. electrical machine design51. electrolysis and storage of batteries52. electric traction53. transmission and distribution
7101. It is noticed that durum charging___________?
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A. the anode becomes chocolate brown in colour (PbCfe) and cathode becomes grey metallic lead (Pb)

B. all of the above

C. energy is absorbed by the cell

D. specific gravity of H2SO4 is increased

E. there is a rise in voltage

7102. During the charging of a lead-acid cell__________?
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A. specific gravity of H2SO4 decreases

B. its voltage increases

C. its cathode becomes dark chocolate brown in colour

D. it gives out energy

7103. Level of electrolyte in a cell should be ________ the level of plates
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A. above

B. equal to

C. none of the above

D. below

7104. Which among the following constitutes the major load for an automobile battery _________?
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A. Self starter

B. Brake light

C. Parking lights

D. Spark plugs

7105. It is noticed that during discharging the following does not happen___________?
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A. both anode and cathode become PbS04

B. specific gravity of H2SO4 decreases

C. voltage of the cell decreases

D. the cell absorbs energy

7106. As compared to a lead-acid cell, the efficiency of a nickel-iron cell is less due to its__________?
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A. lower e.m.f.

B. higher internal resistance

C. small quantity of electrolyte used

D. compactness

7107. The open circuit voltage of any storage cell depends wholly upon___________?
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A. its chemical constituents

B. its temperature

C. on the strength of its electrolyte

D. all above
7108. Capacity of dry cells is_________?
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A. none of the above

B. unaffected by the type of discharge

C. more when it is supplying current for intermittent periods

D. more when it is supplying current for continuous periods

7109. Shelf life of a small dry cell is___________?
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A. less than that of large dry cell

B. none of the above

C. equal to that of large dry cell

D. more than that of large dry cell

7110. Charging of sulfated battery produces _________ heat
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A. very little

B. less

C. more

D. no

7111. In a lead-acid cell, lead is called as____________?
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A. none of the above

B. passive material

C. negative active material

D. positive active material

7112. In constant-current charging method, the supply voltage from discharged to fully charged condition____________?
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A. decreases

B. remains constant

C. none of the above

D. increases
7113. A typical output of a solar cell is_____________?
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A. 0.26 V

B. 2 V

C. 0.1V

D. 1.1 V

7114. Internal short circuits are caused by___________?
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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

7115. When the lead-acid cell is fully charged, the electrolyte assumes _______ appearance
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A. reddish

B. bright

C. dull

D. milky
7116. Life of the batteries is in the following ascending order____________?
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A. Nickel-cadmium cell, Edison cell, lead-acid cell

B. Lead-acid cell, Nickel-cadmium cell, Edison cell

C. Edison cell, Nickel-cadmium cell, lead-acid cell

D. Lead-acid cell, Edison cell, Nickel cadmium cell
7117. Specific gravity of electrolyte in Edison cell is_____________?
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A. 0.8

B. 1.1

C. 0.95

D. 1.21
7118. Battery charging equipment is generally installed______________?
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A. as near as practical to the battery being charged

B. in clean and dry place

C. in location having all above features

D. in well ventilated location

7119. If a battery is wrongly connected on charge following will happen__________?
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A. current drawing will be very small

B. current delivered by the battery will be high

C. current drawing will be nil

D. current drawing will be very high
7120. Trickle charging of a storage battery helps to___________?
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A. keep it fresh and fully charged

B. maintain proper electrolyte level

C. prevent sulphation

D. increase its reserve capacity

7121. 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
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A. 4 parts of acid to 4 parts of water

B. 4 parts of acid to 6 parts of water

C. 6 parts of acid to 4 parts of water

D. 4 parts of acid to 8 parts of water

7122. The effect of sulphation is that the internal resistance__________?
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A. decreases

B. increases

C. none of the above

D. remains same

7123. The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity. The statement is associated with____________?
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A. Faradays law of electromagnetic

B. Faradays law of electrolysis

C. Gausss law

D. Newtons law

7124. A dead storage battery can be revived by___________?
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A. a dose of H2SO4

B. none of the above

C. adding so-called battery restorer

D. adding distilled water

7125. Each cell has a vent cap________?
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A. to add water to the cell if needed

B. to check the level of electrolyte

C. to allow gases out when the cell is on charge

D. to do all above functions
7126. Following will happen if the specific gravity of electrolyte becomes more than 1.23
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A. All above

B. Loss of life

C. Corrosion of the grids of the plate

D. Loss of capacity

7127. Excessive formation of lead sulphate on the surface of the plates happens because of___________?
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A. low level of electrolyte

B. all above

C. persistent undercharging

D. allowing a battery to stand in discharged condition for a long time

E. topping up with electrolyte

7128. Cells are connected in series in order to_____________?
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A. increase the life of the cells

B. increase the voltage rating

C. none of the above

D. increase the current rating

7129. In a battery cover is placed over the element and sealed to the top of the battery container. This is done____________?
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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

7130. While preparing electrolyte for a lead-acid battery___________?
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A. water is poured into acid

B. anyone of the two can be added to other chemical

C. acid is poured into water
7131. Five 2 V cells are connected in parallel. The output voltage is__________?
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A. 2 V

B. 1.75 V

C. 1 V

D. 1.5 V

7132. Which of the following factors adversely affects the capacity of the leadacid battery ?
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A. Temperature of surroundings

B. Specific gravity of electrolyte

C. Rate of discharge

D. All of the above
7133. On overcharging a battery____________?
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A. it will increase the capacity of the battery

B. none of the above will occur

C. it will raise the specific gravity of the electrolyte

D. it will bring about chemical change in active materials

7134. The substances which combine together to store electrical energy during the charge are called ________ materials
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A. active

B. passive

C. inert

D. dielectric

7135. On the average the ampere-hour efficiency of an Edison cell is about__________?
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A. 70%

B. 40%

C. 80%

D. 60%

7136. The internal resistance of a lead-acid cell is that of Edison cell____________?
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A. equal to

B. less than

C. more than

D. none of the above

7137. The capacity of a battery is expressed in terms of____________?
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A. voltage rating

B. current rating

C. none of the above

D. ampere-hour rating
7138. When the load resistance equals the generator resistance which of the following will be maximum __________?
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A. Efficiency of the circuit

B. Power in the load resistance

C. Current

D. Voltage across the load resistance

7139. When two batteries are connected in parallel, it should be ensured that___________?
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A. they have same ampere-hour capacity

B. they have identical internal resistance

C. they have same e.m.f.

D. they have same make

7140. Those substances of the cell which take active part in chemical combination and hence produce electricity during charging or discharging are known as________materials
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A. passive

B. active

C. redundant

D. inert

7141. Ampere hour capacity of an industrial battery is based on _______ hours discharge rate
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A. 8

B. 24

C. 12

D. 16

7142. ______ of electrolyte indicates the state of charge of the battery
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A. specific gravity

B. viscosity

C. mass

D. colour

7143. In alkaline cell the electrolyte is_____________?
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A. KOH

B. concentrated sulphuric acid

C. NaOH

D. dilute sulphuric acid

7144. If a lead-acid cell is discharged below 1.8 V the following will happen.____________?
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A. Capacity of cell will reduce

B. All above will occur

C. Internal resistance will increase

D. Sulphation of plates will occur

7145. Which of the following is incorrect ?
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A. A primary cell has an irreversible chemical reaction

B. A carbon-zinc cell has unlimited shelf life

C. A lead-acid cell can be recharged

D. A storage cell has a reversible chemical reaction

7146. The current flow through electrolyte is due to the movement of____________?
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A. electrons

B. ions

C. none of the above

D. holes

7147. The lead-acid cell should never be discharged beyond____________?
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A. 2 V

B. 1.8 V

C. 2.1 V

D. 1.9 V

7148. The specific gravity of electrolyte is measured by____________?
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A. a mechanical gauge

B. psychrometer

C. manometer

D. hydrometer
7149. Sulphated cells are indicated by____________?
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A. the loss of capacity of the cell

B. the decrease of the specific gravity

C. the low voltage of the cell on discharge

D. all above conditions
7150. The active materials on the positive and negative plates of a fully charged lead-acid battery are_______?
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A. none of the above

B. lead peroxide and lead

C. lead and lead peroxide

D. lead sulphate and lead