Cells and Batteries MCQs with Answers

1. Separators are usually placed between opposing plates in leads acid cells to: 

A.  prevent the electrodes from touching
B.  prevent current flow through the cell
C.  ensure that the positive and negative electrodes are connected
D.  help with the polarization effect during discharge


2. Gel-type and paste-type electrolytes have become common in lead-acid cells because they: 

A.  allow the cells to be a larger physical size
B.  spills and overflow from liquid types
C.  generate extra voltages to assist the output
D.  enable the chemical action to dissipate into the plates


3. Look at the following diagram:      
With reference to the cut-away drawing of a lead-acid cell shown in figure 1, the space at the bottom of the plates is to: 

A.  ensure that any sludge that form will combine with the plates
B.  enable the electrolyte to form extra electrodes at the bottom
C.  prevent any sludge formation from shorting the plates
D.  prevent the electrolyte form touching the bottom of the plates.


4. Generally speaking, the difference between a primary and secondary cells is that a secondary cell: 

A.  is smaller for the same output capacity
B.  will produce alternating current
C.  has a liquid electrolyte
D.  can be recharged


5. To produce a higher output voltage cells are connected: 

A.  in series
B.  in parallel
C.  with their positive terminals together
D.  so that some are open circuited


6. The number of 1.5 volt cells required to be connected in series to give an output of 9 volts is: 

A.  9
B.  6
C.  13
D.  18


7. When two or more strings of cells, or batteries of cells, are connected in parallel in order to increase the available current, they are known as: 

A.  a mob of cells
B.  lead-acid cells
C.  banks of batteries
D.  a series string


8. Thirty-six, 2 V, lead–acid cells have been connected in banks of batteries to produce a 24 V supply. The number of banks of batteries will be: 

A.  24
B.  12
C.  6
D.  3


9. The ‘nominal voltage’ of a cell is the voltage that the cell should produce with: 

A.  zero current flowing
B.  full load current
C.  load current
D.  a small or nominal load connected


10. The output voltage of a cell changes when a current is drown from the cell, due to the voltage drop across the: 

A.  resistance of the connected load
B.  internal resistance of the cell
C.  inductance of the connected load
D.  ac supply charging the cell


11. The internal resistance of a cell will have a voltage drop across it that adds to the nominal voltage during the charging cycle and: 

A.  adds to the nominal voltage during the discharge cycle
B.  assists the nominal voltage during the discharge cycle
C.  subtracts from the nominal voltage during the discharge cycle
D.  subtracts from the nominal voltage during the charging cycle


12. Look at the following diagram:    
With reference to the terminal voltage-drop chart shown in figure 2, if a load current of 40 A is drawn from a 12 V battery with an internal resistance of 0.05 W, then the terminal voltage will be: 

A.  6 V
B.  11.5 V
C.  8 V
D.  10 V


13. Generally, the energy that a cell can store depends on the type of cell chemically and the: 

A.  physical size of the plates
B.  type of positive terminal
C.  voltage of the cell
D.  current that the cell can deliver


14. By convention, the energy stored in a cell is measured in: 

A.  volt-amps
B.  ampere-hours
C.  ohm-hours
D.  amps per volt


15. The capacity of a lead-acid battery depends on the discharge rate of the battery. A high discharge rate: 

A.  increases the storage capacity
B.  will maintain a high storage capacity
C.  decreases the storage capacity
D.  improves the output voltage with each charge


16. When mixed ready for use in a lead-acid battery, the specific gravity of the diluted sulphuric acid is: 

A.  1.125
B.  1.150
C.  1.225
D.  1.250


17. Look at the following photo:      
With reference to figure 3, the picture shows a person carrying out: 

A.  an electrolyte specific gravity test on a battery
B.  a voltage test on a car battery
C.  a current load test on a battery using a dummy load
D.  an electrolyte voltage availability battery test


18. The state of charge of a battery can often be determined from the: 

A.  length of time in use
B.  condition of the electrolyte
C.  date code on the battery
D.  no-load current level of the cells


19. One type of battery that is rapidly degraded by excessive and repetitive deep discharges is: 

A.  a stand-alone power supply battery
B.  a rechargeable battery for a power tool
C.  an automotive battery
D.  a battery for an electric vehicle


20. Look at the following table:    
With reference to the specific energy table shown in figure 4, the type of cell with the highest energy per kilogram is: 

A.  sealed zinc-mercury cell
B.  silver oxide-cadmium
C.  lead-acid cell
D.  silver-zinc cell


21. In automotive terms, the maximum current expected from a battery is called the: 

A.  cold cranking amps
B.  cold crankcase amps
C.  continuous cranking amps
D.  crankcase consolidated alternator


22. The efficiency of a battery can be determined using the formula,
percentage efficiency = 

A.  input/output x 100
B.  output/input x 100
C.  input x output/100
D.  output x input/100


23. The cycle-life of a battery is the number of times they can be: 

A.  used on an electric bicycle
B.  recycled when no longer serviceable
C.  discharged and recharged
D.  used before damaging a battery power tool


24. Some of the dangers that must not be ignored for when working with cells and batteries are: 

A.  electric shock
B.  chemical burns
C.  explosive conditions
D.  all of the given answers


25. While charging, batteries can vent off a gas such as: 

A.  hydrogen
B.  carbon dioxide
C.  carbon monoxide
D.  chlorine


26. Lead-acid batteries and alkaline batteries should be kept separated, as the mixing of acids and alkaline can lead to: 

A.  flat batteries
B.  very volatile chemical reactions
C.  increased output capacity in some types
D.  decreased output voltage level in alkaline cells


27. One maintenance procedure with wet cells is to regularly check the electrolyte level because if they are not kept covered they will: 

A.  produce excessive voltage
B.  increase the cell capacity
C.  dry out
D.  consume the electrolyte


28. Cells that are getting old typically have: 

A.  a higher output voltage
B.  a lower internal resistance
C.  larger amount of electrolyte
D.  an increasing internal resistance


29. The electrolyte in the zinc-alkaline cell is 

A.  potassium hydroxide
B.  amalgamated zinc granules
C.  compacted manganese dioxide
D.  graphite powder


30. In the zinc-mercury type of cell, the negative electrode is made from: 

A.  of potassium hydroxide
B.  amalgamated zinc
C.  mercuric oxide
D.  spongy lead


31. When compared with other types, the lithium cell’s output voltage tends to: 

A.  increase at a slow rate over the cell’s lifecycle
B.  decrease at a rapid rate over the cell’s lifecycle
C.  remain more constant over the cell’s lifecycle
D.  become unstable at different times over the cell’s lifecycle


32. When compared with other types of cell of comparable size and weight, lead-acid cells can deliver: 

A.  higher voltages for longer times
B.  only about half the current of the others
C.  full current for prolonged periods of time
D.  higher current for short bursts


33. As the active materials of a lead-acid cell have no rigid mechanical form or strength they are mounted in a lead grid. The grid usually has antimony added to the lead: 

A.  for rigidity and extra mechanical strength
B.  to help keep the internal resistance low
C.  to increase the out capacity of the cell
D.  in order to prevent polarisation during charging


34. During the discharge cycle of a lead-acid cell, the sulphuric acid electrolyte ionises in the water to form positive hydrogen ions and: 

A.  positive sulphur-dioxide ions
B.  negative sulphate ions
C.  positive sulphate ions
D.  negative lead ions


35. Once a lead-acid cell is fully charged, the hydrogen and oxygen, being liberated cannot combine within the cell and: 

A.  will now combine outside the cell
B.  regenerate into the positive and negative electrodes
C.  vent to the atmosphere as gas
D.  assist with the depolarisation effect


36. For successful operation, the sealed lead-acid cell must be charged at a rate that will: 

A.  cause the gas to build up a good pressure within the cell
B.  ensure that the gas pressure within the cell does not fall below the set level
C.  enable the voltage on the plates to undergo a transfer characteristic effect
D.  not cause any gas to build up excessive pressure within the cell


37. One advantage of the lead-acid cell with a gel electrolyte is that they can be used: 

A.  in any position
B.  when completely discharged
C.  for a longer period on high currents
D.  when an ac supply is required


38. There are two major types of nickel-alkaline cells. One has nickel-iron electrodes and the other has: 

A.  nickel-lead electrodes
B.  nickel-cadmium electrodes
C.  plain lead electrodes
D.  pure alkaline electrodes


39. One advantage of the nickel-metal hydride cell secondary cell is that it: 

A.  has a limited shelf life
B.  does not maintain a high output voltage during discharge
C.  is capable of many charge/recharge cycles
D.  has a memory effect


40. The modern fuel cell gives more energy per unit mass than a storage battery and in addition: 

A.  the electrodes of platinum black undergo a chemical change
B.  has the same output voltage as a lead-acid cell
C.  is very inexpensive to manufacture
D.  water is produced as a useful by product


41. The main requirements for batteries for standby power supplies are they must have a long life with a low self-discharge rate and: 

A.  lose a minimum of electrolyte over long periods
B.  generate a good volume of hydrogen during charging
C.  be able to be used in any position
D.  have a robust construction so they can be frequently moved