Cell And Battery Multiple Choice Questions and Answers-2021

أبريل 16, 2021

1. The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity which passes through the electrolyte".
The above statement is associated with
(A) Webers and Ewings theory
(B) Laplace law
(C) Faraday's laws of Electrolysis
(D) Gauss's theorem.

Ans: (C) Faraday's laws of Electrolysis

2. For all substances Chemical equivalent Electrochemical equivalent
(A) 96500 coulombs
(B) 9650 coulombs
(C) 965 coulombs
(D) 96.5 coulombs.

Ans: (A) 96500 coulombs

3. 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

Ans: (C). Ampere hour rating

Explanation:
Battery capacity is measured in amps × hours (AH). For example, if a battery has 250 AH capacity and provides 2 A average current to a load, in theory, the battery will last 125 hours.

4. 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

Ans: (C). Lead-acid battery

Explanation:
The storage battery generally used in an electric power station is Lead-acid battery. It is cost-effective and provides a steady electric current for a long-time period. The Components used in this battery are Lead Peroxide, Sponge lead and Dilute Sulphuric Acid.

5. Trickle charger of a storage battery helps to
(A). Maintain proper electrolyte level
(B). Increase its reverse capacitor
(C). Prevent sulphation
(D). Keep it fresh and fully charged

Ans: (D). Keep it fresh and fully charged

Explanation:
In case of car batteries, trickle charging prevents the deadly process of sulfation. Battery performance depends on its temperature. Current passed to the battery during trickle charging keeps it at optimum temperature. The low current of trickle charge ensures that there is no overheating of your battery.

Trickle charging : A trickle chargers' primary purpose is to slowly charge a battery and prevent overcharging – however, the same result can be achieved through the use of a standard charger. If storing batteries for a period of time is a common activity, then it's safe to say a trickle charger may be a good investment.

6. The plates of a lead-acid battery are made of
(A) rolled zinc-copper alloy
(B) cast antimonial lead alloy
(C) perforated nickel-cadmium alloy
(D) pressed antimony bismuth alloy.

Ans: (B) cast antimonial lead alloy

7. In a lead-acid battery, separators are provided
(A) to reduce tendency for polarisation
(B) to facilitate flow of current
(C) to reduce internal resistance
(D) to avoid internal short circuits.

Ans: (D) to avoid internal short circuits.

8. The container of a lead-acid battery is made of
(A) molded hard rubber
(B) ceramics
(C) celluloid
(D) any of the above.

Ans: (D) any of the above.

9. Fillers in a lead-acid battery are provided
(A) to prevent flow of gases
(B) to facilitate flow of gases
(C) to recover acid loss through vapours
(D) all of the above.

Ans: (B) to facilitate flow of gases

10. In the case of a lead-acid battery, during discharging

(A) both anode and cathode become PbSo4

(B) specific gravity of acid increases

(C) voltage of the cells increases

(D) none of the above takes place.

Ans: (A) both anode and cathode become PbSo4

11. On overcharging a battery

(A). It will bring about chemical change inactive 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

Ans: (D). None of the above

Explanation:
As a result of too high a charge voltage excessive current will flow into the battery, after the battery has reached full charge. This will cause decomposition of the water in the electrolyte and premature aging. At high rates of overcharge a battery will progressively heat up.

12. 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

Ans: (D). In location having all above features

Explnation:
The clean and dry place maintains the battery from the short circuit by wet condition. The charging source as possible as be near with the battery. Otherwise, more power loss happens in the electrical wire. Hence, we need the above all features to install the battery charging equipment.

13. Batteries are charged by
(A). Rectifiers
(B). Engine generator sets
(C). Motor generator sets
(D). Any of the above

Ans: (D). Any of the above

Explanation:
A rectifier transforms alternating current (AC) into direct current (DC). Its normal function is charging batteries and keeping them in optimum conditions while, at the same time, providing DC power for other loads.

14. Battery container should be acid resistance therefore it is made up of
(A).Glass
(B). Plastic
(C). Wood
(D). All of the above

Ans: (D). All of the above

Explanation:
The container of the lead acid battery is made of glass, lead-lined wood, ebonite, the hard rubber of bituminous compound, ceramic materials or moulded plastics and are seated at the top to avoid the discharge of electrolyte.

15. In a lead acid battery, during charging

(A) anode becomes whitish in colour

(B) voltage drops

(C) specific gravity of acid increases

(D) the cell gives out energy.

Ans: (C) specific gravity of acid increases

16. The condition of a fully charged lead acid battery can be ascertained by

(A) voltage

(B) specific gravity of electrolyte

(C) gassing

(D) any of the above.

Ans: (D) any of the above.

17. The value of specific gravity of acid when a lead acid battery is fully charged is

(A) 1.285

(B) 2.185

(C) 2.585

(D) 2.9585.

Ans: (A) 1.285

18. The active materials on the positive and negative plates of a fully charged lead acid battery are

(A) pure lead and lead oxide

(B) lead peroxide and lead sulphated

(C) lead peroxide and pure lead

(D) lead sulphate and lead oxide.

Ans: (C) lead peroxide and pure lead

19. A floating battery is one

(A) in which battery voltage is equal to charger voltage

(B) in which the current in the circuit is fully supplied by the battery

(C) which gets charged and discharged simultaneously

(D) which supplies current intermittently and also during off cycle gets charged.

Ans: (D) which supplies current intermittently and also during off cycle gets charged.

20. Which cell has the reversible chemical reaction ?

(A) Lead acid

(B) Mercury oxide

(C) Carbon zinc

(D) Silver oxide.

Ans: (A) Lead acid

21. Which of the following statements is correct?

(A) In a Voltaic cell, the anode and cathode are carbon and zinc rod respectively

(B) Leclanche cell suffers from local action and polarisation

(C) Dry cell is basically a Leclanche cell

(D) Edison alkali cell is a primary cell.

Ans: (C) Dry cell is basically a Leclanche cell

22. During charging, the electrolyte of a lead acid battery becomes

(A) stronger

(B) weaker

(C) diluted with water

(D) there is no change in electrolyte.

Ans: (A) stronger

23. Two cells are connected in series to form a battery. Their internal resistance is 0.1 0. The internal resistance of the battery will be

(A) 0.05 Ω

(B) 0.1 Ω

(C) 0.20 Ω

(D) 0.4 Ω

Ans: (C) 0.20 Ω

Explanation:

Batery cells are connected in series and also internal resistance are also connected in series so total resistance of battery is 0.10 + 0.10 = 0.20 ohms

24. On ampere hour basis the efficiency of a lead acid battery is in the range

(A) 90 to 95 percent

(B) 80 to 85 percent

(C) 70 to 75 percent

(D) 60 to 65 percent.

Ans: (A) 90 to 95 percent

25. In an Edison cell, the electrolyte used is

(A) Sodium chloride

(B) Ammonium sulphate

(C) Potassium hydroxide

(D) Hydrochloric acid.

Ans: (C) Potassium hydroxide

26. The life of a lead-acid battery is expected to be

(A) six month

(B) one year

(C) two to five years

(D) ten to fifteen years.

Ans: (C) two to five years

Explanation:

A secondary battery having a 20 hour charge rate of 10 amperes delivers 5A for 36 hours on discharge with a mean terminal voltage of 1.96 V. The terminal voltage of charging is 2.35 V.

27. Ampere-hour efficiency of the battery is

(A) 60%

(B) 70%

(C) 80%

(D) 90%.

Ans:(D) 90%.

Explanation:

Here

charge gained = ampere * time

= 20 * 10

= 200 Ah

charge lost = ampere * time

= 5 * 36

= 180 Ah

Ampere hour efficiency = charge lost / charge gained * 100

= 180 / 200 * 100

= 0.9 * 100

= 90 %

28. Wat hour efficiency of the battery is

(A) 85%

(B) 75%

(C) 70%

(D) 66%.

Ans: (B) 75%

Explanation:

Power P1 = V1 I1

Battery Power E1 = P1 T1

Hence battery power E1 = V1 I1 T1

= 2.35 * 20 * 10

= 470 Wh

Hence battery power E2 = V2 I2 T2

= 1.96 * 5 * 36

= 352.8 wh

Watt hour efficiency = E2 / E1 * 100

= 352.8 / 470 * 100

= 75 %

29. Following will happen if the battery charging rate is too high

(A). Excessive gassing will occur
(B). Temperature rise will occur
(C). Bulging and buckling of plates we occur
(D). All of the above

Ans: (D). All of the above

Explanation:
If a battery is charged at too high a rate, only part of the current is used to produce the chemical actions by which the battery is charged. The balance of the current decomposes the water of the electrolyte into hydrogen and oxygen, causing gassing. As the bubbles of gas force their way out of the plates, they blow off particles of the active material.

30. Local action in a battery is indicated by
(A). Excessive gassing under load conditions
(B). Excessive drop in the specific gravity of electrolyte even when the sale is on open circuit
(C). Both A and B
(D). None of the above

Ans: (D). None of the above

Explanation:
Local Action : This is caused by the impurities present in zinc rod. When the zinc rod isimmersed in acid, the zinc atoms and the impurity atoms form a large number of local cells and the zinc rod gets consumed even when the cell is not in use. This defect can be avoided by using amalgamated zinc rods.

31. The following indicate that battery on charge has attained full charge
(A). Colour of electrode
(B). Gassing
(C). Specific gravity
(D). All of the above

Ans: (D). All of the above

Explanation:1. The color of the + ve plates will be dark brown. This can be seen only if the battery has a transparent cover.
2. Voltage per cell will be 2.15 volts.
3. Gassing in the will electrolyte will indicate. But the current is splitting up water to H2 and O2. Because the positive and negative plates are fully converted to their original constituents.

32. Which of the following statements is not corect?

(A) A primary cell is an electro-chemical cell

(B) After charging, a primary cell can be again put to use

(C) Dry cell is a primary cell

(D) Leclanche cell is used in experiments, where constant supply of current is not needed.

Ans: (B) After charging, a primary cell can be again put to use

33. The indication of the state of charge of a battery is best given by

(A) specific gravity of electrolyte

(B) temperature of electrolyte

(C) colour of electrolyte

(D) level of electrolyte.

Ans: (A) specific gravity of electrolyte

34. Common impurity in battery electrolyte is

(A) sodium chloride

(B) iron

(C) lead sulphate

(D) dust.

Ans: (B) iron

35. Open circuit voltage of a fully charged lead-acid cell is

(A) 1.9 V

(B) 2.0 V

(C) 2.7 V

(D) 2.5 V.

Ans: (C) 2.7 V

36. The capacity of storage battery is expressed as

(A) the number of recharges it can take

(B) time for which it can be used

(C) the number of cells it contains

(D) ampere hour it can deliver.

Ans: (D) ampere hour it can deliver.

37. On walt hour basis the efficiency of a lead acid battery is in the range

(A) 90 to 95 percent

(B) 80 to 85 percent

(C) 70 to 85 percent

(D) 60 to 70 percent.

Ans: (C) 70 to 85 percent

38. What is the arrangement to get the maximum current in 3 ohm resistance in the case of 24 cells, each of internal resistance 2 ohms?

(A) 12 cells in series with two rows in parallel

(B) 3 cells in series with three rows in parallel

(C) 6 cells in series with four rows in parallel

(D) 4 cells in series with six rows in parallel.

Ans: (C) 6 cells in series with four rows ill parallel

Explanation:

39. Trickle charge is required for

(A) lead acid batteries

(B) nickel iron cells

(C) primary cells

(D) all of the above.

Ans: (D) all of the above.

40. A wet battery cover in case of lead acid battery indicates

(A) excessive gassing during charging

(B) leaky seals at covers

(C) overfilling of the battery

(D) any of the above.

Ans: (D) any of the above.

41. Internal resistance of a battery is due to

(A) resistance of electrolyte

(B) resistance of electrodes

(C) surface contact resistance

(D) all of the above.

Ans: (D) all of the above.

42. The e.m.f. of a storage battery depends upon

(A) size of the electrodes

(B) shape of the cell

(C) nature of electrodes

(D) all of the above.

Ans: (C) nature of electrodes

43. The internal resistance of a dry cell is of th order of

(A) 0.2 to 0.4 ohm

(C) 2 to 5 ohms

(B) 1 to 1.5 ohm

(D) 1 to 15 ohms.

Ans: (A) 0.2 to 0.4 ohm

44. Proper charging rate for lead acid battery is

(A) 1/2 of rated ampere hour capacity

(B) 1/3 of rated ampere hour capacity

(C) 1/4 of rated ampere hour capacity

(D) 1/8 of rated ampere hour capacity.

Ans: (D) 1/8 of rated ampere hour capacity.

45. For a group of cells when internal resistance of the group is equal to the external resistance due to load, the battery will give

(A) maximum voltage

(B) maximum current

(C) maximum energy

(D) maximum ampere-hours.

Ans: (B) maximum current

46. One ampere hour charge is equivalent to

(A) 36 coulombs

(B) 360 coulombs

(C) 3600 coulombs

(D) 36000 coulombs.

Ans: (C) 3600 coulombs

47. When water is added to sulphuric acid

(A) colour of acid changes

(B) lot of heat is generated

(C) water starts boiling

(D) acid particles get separated.

Ans: (B) lots of heat is generated

48. To prevent local action in battery, only ............is used in electrolytes
(A). Pump water
(B). Distilled water
(C). Tap water
(D). Both A and C

Ans: (B). Distilled water

Explnation:
To prevent local action in a battery, only distilled water is used in electrolytes.

Local Action : This is caused by the impurities present in zinc rod. When the zinc rod isimmersed in acid, the zinc atoms and the impurity atoms form a large number of local cells and the zinc rod gets consumed even when the cell is not in use. This defect can be avoided by using amalgamated zinc rods.

49. Ampere hour capacity of an industrial battery is based on ..........hours discharge rate
(A). 8
(B). 12
(C). 16
(D). 24

Ans: (A). 8

Explanation:
The amp-hour is a unit of battery energy capacity, equal to the amount of continuous current multiplied by the discharge time, that a battery can supply before exhausting its internal store of chemical energy.

50. A battery of six cells will show a drop of ........volts from fully charged state to fully discharged state
(A). 1
(B). 1.5
(C). 2.4
(D). 2.9

Ans: (C). 2.4

51. 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

Ans: B. Nickel-iron battery

Explanation:
Lead-acid batteries are often used as the main battery(s) in an aircraft. Nickel Cadmium (NiCd). Nickel-cadmium cells have an anode made of cadmium hydroxide and a cathode of nickel hydroxide that are immersed in an electrolyte made up of potassium, sodium and lithium hydroxides.

52. When two batteries are connected in parallel, it should be ensured that
(A). They have same emf
(B). They have same make
(C). They have same ampere hour capacity
(D). They have identical internal resistance

Ans: A. They have same emf

Explanation:
When connecting batteries in parallel the negative terminal of one battery is connected to the negative terminal of the next and so on through the string of batteries, the same is done with positive terminals, ie positive terminal of one battery to the positive terminal of the next.

When batteries are connected in parallel, the voltage remains the same, but the current that can flow in the circuit increases.

53. If a battery is to be charged at a much higher rate as compared to normal charging rate, the charging should be restricted to
(A). 95% of the capacity of battery
(B). 80% of the capacity of battery
(C). 55% of the capacity of battery
(D). 35% of the capacity of battery

Ans: (B). 80% of the capacity of battery

54. A floating battery is one
(A). Which gets charged and discharged simultaneously
(B). Which supplies current intermittently and also during off-cycle gets charged
(C). In which battery voltage is equal to charger voltage
(D). In which the current in the circuit is fully supplied by the battery

Ans: (B). Which supplies current intermittently and also during off-cycle gets charged

55. The electro-chemical reactions are not reversible in case of
(A) primary cells only
(B) secondary cells
(C) both primary and secondary cells.

Ans: (A) primary cells only

56. The energy in a lead acid battery is stored in the form of

(A) electrostatic charge

(B) Don-flowing current

(C) chemical energy

(D) nuclear energy.

Ans: (C) chemical energy

57. The electrolyte in a Leclanche cell is

(A) dilute hydrochloric acid

(B) aqueous solution of ammonium chloride

(C) pyrogallic acid

(D) lead stearate.

Ans: (B) aqueous solution of ammonium chloride

58. The electrode for a battery must be

(A) a good conductor of electricity

(B) a bad conductor of electricity

(C) a semi-conductor

(D) an insulator

Ans: (A) a good conductor of electricity

59. For a discharged lead-acid battery, the specific gravity of the acid is

(A) 0.9

(B) 1.0

(C) 1.12

(D) 1.3.

Ans: (C) 1.12

60. In a lead accumulator, the plates are placed close to each other, as :

(A) it makes the lead accumulator sturdy

(B) it increases the e.m.f. of the accumulator

(C) it decreases the internal resistance of the accumulator

(D) it increases the life span of the accumulator.

Ans: (C) it decreases the internal resistance of the accumulator

61. Even when not in use, the self-discharge of a battery occurs at the rate of

(A) 0.5 to 1% of rated capacity per hour

(B) 0.5 to 1% of rated capacity per day

(C) 0.5 to 1% of rated capacity per week

(D) 0.5 to 1% of rated capacity per month.

Ans: (B) 0.5 to 1% of rated capacity per day

62. The specific gravity of acid is checked with the help of a

(A) hygrometer

(B) lactometer

(C) hydrometer

(D) cell tester

Ans: (C) hydrometer

63. Which of the following statements is not correct? A lead accumulator of 20-ampere hour can supply

(A) 20 A of current for 20 hours

(B) 1 A of current for 20 hours

(C) 20 A of current for 1 hour

(D) 0.1 A of current for 200 hours.

Ans: (A) 20 A of current for 20 hours

64. The term trickle charge is associated with

(A) dry cells

(B) silver zinc batteries

(C) lead acid batteries

(D) nickel iron batteries.

Ans: (C) lead acid batteries

65. When the battery is being charged. the terminal voltage decreases with

(A) increasing charging rate

(B) increasing state of charge

(C) increasing temperature

(D) all of the above.

Ans: (C) increasing temperature

66. When the battery is being discharged, the terminal voltage decreases with

(A) decreasing discharge rate

(B) decreasing state of charge

(C) decreasing temperature

(D) none of the above.

Ans: (A) decreasing discharge rate

67. The ampere hour capacity of a battery used on cars is

(A) 5-10 Ah

(B) 30 - 60 Ah

(C) 100 - 150 Ah

(D) 200-250 Ah.

Ans: (B) 30 - 60 Ah

68. The ampere hour capacity of a battery used on trucks is

(A) 5 - 10 Ah

(B) 30-60 Ah

(C) 100-150 Ah

(D) 200-250 Ah.

Ans: (C) 100-150 Ah

69. Which battery is used in aeroplanes ?

(A) Dry cell battery

(B) Lead acid battery

(C) Edison cell

(D) None of the above.

Ans: (D) None of the above.

70. Which test is listed to ascertain whether the battery plates are defective or not?

(A) Cadmium test

(B) High discharge test

(C) Open volt test

(D) Specific gravity test.

Ans:(A) Cadmium test

71. Which of the following is the common voltage of automobile batteries

(A)2 V

(B) 10 V

(C) 12 V

(D) 25 V.

Ans: (A)2 V

72. Cells are connected in parallel to

(A) increase the voltage output

(B) increase the internal resistance

(C) decrease the current capacity

(D) Increase the current capacity

Ans: (D) Increase the current capacity

73. A constant voltage source has

(A) low internal resistance

(B) high internal resistance

(C) minimum efficiency

(D) minimum current capacity.

Ans: (A) low internal resistance

74. Which of the following is false ?

(A) A carbon-zinc cell has unlimited self life

(B) A lead-acid cell can be recharged

(C) A storage cell has an irreverse chemical reaction

(D) A primary cell has an irreversi chemical reaction.

Ans: (A) A carbon-zinc cell has unlimited self life

75. The current in a chemical cell is a moveme of

(A) positive hole charges

(B) positive ions only

(C) negative ions only

(D) positive and negative ions.

Ans: (D) positive and negative ions.

76. Cells are connected in series to

(A) increase the voltage output

(B) decrease the voltage output

(C) decrease the internal resistance

(D) increase the current capacity.

Ans: (A) increase the voltage output

77. Which of the following is a dry storage cell ?

(A) Mercury cell

(B) Nickel-cadmium cell

(C) Carbon-zinc cell

(D) Edison cell.

Ans: (B) Nickel-cadmium cell

78. Two batteries having unequal emf

(A) cannot be connected in parallel

(B) cannot be connected in series

(C) can be connected in series only

(D) maybe connected in parallel or series.

Ans: (C) can be connected in series only

79. The terminal voltage when the battery is being charged decreases with
(A). Increasing temperature
(B). Increasing charging rate
(C). Increasing stage of charge
(D). All of the above

Ans: (A). Increasing temperature

Explanation:
Whenever a battery is being charged, the terminal voltage of the battery changes a small amount whenever the battery temperature changes. As the battery temperature increases, its terminal voltage decreases or as the terminal voltage decreases, its temperature increases.

80. Which test is used to ascertain whether the battery plates are defective or not ?
(A). Open volt test
(B). Cadmium test
(C). High discharge test
(D). Specific gravity test

Ans: (B). Cadmium test

81. The electrode for a battery must be
(A). A semiconductor
(B). An insulator
(C). A good conductor of electricity
(D). A bad conductor of electricity

Ans: (C). A good conductor of electricity

Explanation:
Electrodes are typically good electric conductors, but they need not be metals. In an electrochemical cell, reduction and oxidation reactions take place at the electrodes. Batteries contain a variety of electrodes, depending on the battery type. Lead-acid batteries are based on lead electrodes.

82. Cells are connected in series in order to
(A). Increase the voltage rating
(B). Increase the current rating
(C). Increase the life of the cells
(D). None of the above

Ans: (A). Increase the voltage rating

Explanation:
When connecting the cells in series, according to Kirchhoff's law the voltage across the cells can be increased. At the same time, the electric current capacity of the cells will be of the same capacity of the single cell. (In series same current with increased voltage).

83. Which of the following material is used in solar cells?

(A) Silicon

(B) Barium

(C) Selenium

(D) Silver

Ans: (A) Silicon

84. The efficiency of a solar cell can be expected in the range

(A) 10 to 15 percent

(B) 25 to 35 percent

(C) 45 to 60 percent

(D) 70 to 85 percent.

Ans: (A) 10 to 15 percent

85. The output voltage of a silver oxide cell is

(A) 1.1 volt

(B) 1.2 volt

(C) 1.5 volt

(D) 1.71 volt.

Ans: (C) 1.5 volt

86. In a lithium cell the positive electrode is made of

(A) zinc dust

(B) stainless steel

(C) spongy iron

(D) carbon.

Ans: (D) carbon.

87. Which efficiency of a battery is more than the remaining ?

(A) Watt hour efficiency

(B) Ampere hour efficiency

(C) Overall efficiency

(D) (A), (B) and (C) above have the same value.

Ans: (B) Ampere hour efficiency

88. While comparing alkaline batteries, with lead acid batteries, which one of the following can be cited as the advantage of the former over the latter?

(A) Low initial cost

(B) Electrical robustness

(C) High output voltage

(D) All of the above.

Ans:(B) Electrical robustness

89. A fuel cell converts ........... energy into electrical energy

(A) chemical

(B) mechanical

(C) solar

(D) magnetic.

Ans: (A) chemical

90. In a lead-acid cell, hydrogen is liberated at

(A) negative plate

(B) positive plate

(C) both negative and positive plates

(D) none of the plates.

Ans: (A) negative plate

91. In a lead-acid cell PbSO4 is formed during

(A) charging only

(B) discharging only

(C) both during charging as well discharging

(D) neither during discharging nor charging

Ans: (B) discharging only

92. To keep the terminals of a lead-acid storage battery free from corrosion, it is advisable to

(A) apply petroleum jelly

(B) dini boles on the terminal top

(C) keep the electrolyte level low

(D) charge the battery at frequent intervals.

Ans: (A) apply petroleum jelly

93. 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

Ans: (D). 2 V

Explanation:
When two or more batteries are placed in parallel, the voltage in the circuit is the same as each individual battery. That is five or more 2 volt batteries in parallel will produce a voltage of 2 Volts!

94. A dead storage battery can be revived by
(A). Adding distilled water
(B). Adding so-called battery restorer
(C). A dose of H2SO4
(D). None of the above

Ans: (D). None of the above

Explanation:
Attach a battery trickle charger or a computerized smart charger to your old lead acid battery, and allow charging continuously for about a week to 10 days. The extremely slow charging rates dissolve the de-sulphation that kills the battery, and revives it back to being able to hold a usable charge.

95. 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 of the above

Ans: (D). All of the above

Explanation:
Open-circuit voltage (abbreviated as OCV or VOC ) is the difference of electrical potential between two terminals of a device when disconnected from any circuit. ... Alternatively, the open-circuit voltage may be thought of as the voltage that must be applied to a solar cell or a battery to stop the current.

96. 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

Ans: (D). To do all above functions

Explanation:
A battery vent tube is attached to the battery so it can expel those gases out into the open air away from the car. ... The metal case of the battery has a hole, or safety vent on it. Once the pressure inside is too high the vent pops and let's the gas out. This is called venting.

97. Cell short circuit results in
(A). Low specific gravity electrolyte
(B). Abnormal high-temperature
(C). Reduced gassing on charge
(D). All of the above

Ans: (D). All of the above

98. Internal resistance of a cell is reduced to by
(A). Using vent plug to permit gas formed during discharge
(B). Increasing the plate area
(C). Putting plates very close together
(D). All of the above

Ans: (D). All of the above

Explanation:
The internal resistance (IR) of a battery is defined as the opposition to the flow of current within the battery. There are two basic components that impact the internal resistance of a battery; they are electronic resistance and ionic resistance.The internal resistance of battery reduced by using vent plug to permit gas formed during dicharge, increasing the plate area and putting plates very close together.

99. When cells are connected in parallel grouuping, then

(A) Current-capacity decreases

(B) Current capacity increases

(C) EMF increases

(D) EMF decreases.

Ans: (B) Current capacity increases

100. For cadmium plating cathode current density is usually restricted to

(A) 1 to 3 amperes/ dm2

(B) 5 to 10 amperes / dm2

(C) 10 to 15 amperes/dm2

(D) 25 amperes/dm2

Ans: (A) 1 to 3 amperes/ dm2

101. Out of the following which one will have the lowest cathode current density ?

(A) Zinc plating

(B) Cadmium plating

(C) Silver plating.

Ans:(C) Silver plating.

102. Out of the following which one will have the highest anode current density ?

(A) Zinc plating

(B) Cadmium plating

(C) Silver plating.

Ans: (A) Zinc plating

103. For zinc plating the anode current density is usually

(A) 05 10 1 A/dm²

(B) 2 to 4 A/dm²

(C) 5 10 10 A/dm2

(D) 10 to 20 A/dm².

Ans: (B) 2 to 4 A/dm²

104. Electrolyte for silver plating is

(A) double cyanide of silver and potassium solution

(B) dilute sulphuric acid

(C) potassium nitrate solution

(D) any of the above.

Ans: (A) double cyanide of silver and potassium solution

105. For nickel plating the electrolyte consists of

(A) double sulphate of nickel and ammonium

(B) double cyanide of potassium and silver solution

(C) cupronickel sulphate

(D) any of the above.

Ans: (A) double sulphate of nickel and ammonium

106. For cadmium plating electrolyte used is

(A) sodium cyanide, cadmium and caustic soda

(B) cadmium hexal meta phosphate

(C) cadmium sulphate and sulphuric acid

(D) any of the above.

Ans: (A) sodium cyanide, cadmium and caustic soda

107. Zinc plating solution consists of

(A) Zinc, sodium cyanide and sodium hydroxide solution

(B) Zinc chloride and ammonium hydroxide

(C) Zinc sulphate and dilute sulphuric acid

(D) any of the above.

Ans: (A) Zinc, sodium cyanide and sodium hydroxide solution

108. A external resistance R is connected to a cell of internal resistance r, then the current is maximum when

(A) R<r

(B) R>

(C) R=r

(D) none of the above.

Ans: (C) R=r

109. EMF of cell depends upon.

(A) External resistance

(B) Intemal resistance

(C) Electrolyte

(D) Area of plates inside electrolyte.

Ans: (C) Electrolyte

110. Voltage required for barrel plating is usually

(A) 3 to 5 volts

(B) 6 to 16 volts

(C) 20 to 50 volts

(D) 50 to 200 volts.

Ans: (B) 6 to 16 volts

111. which of following is not a primary cell ?

(A) carbon zinc

(B) silver Oxide

(C) silver Zinc

(D) Nickel cadmium

Ans: (C) silver Zinc

112. The current flowing between electrodes inside a lead acid battery is

(A) electron current

(B) proton current

(C) ionization current

(D) polarization current

Ans: (D) polarization current

113. Which of the following is plated by barrel plating?

(A) All pins

(B) Gems clips

(C) Steel balls

(D) All of the above.

Ans: (D) All of the above.

114. Which laws find application is electrolysis ?

(A) Coulomb's laws

(B) Van Allen's laws

(C) Faraday's laws

(D) Ohm's laws.

Ans: (C) Faraday's laws

115. The capacity of dry cells is
(A). More when it is supplying current for intermittent periods
(B). More when it is supplying current for a continuous period
(C). Unaffected by the type of discharge
(D). None of the above

Ans: (A). More when it is supplying current for intermittent periods

116. Self Life of a small dry cell is
(A). Equal to that of larger dry cell
(B). Less than that of large dry cell
(C). More than that of large dry cell
(D). None of the above

Ans: B. Less than that of large dry cell

117. The current in a chemical cell is a movement of
(A). Positive ions only
(B). Positive and negative ions
(C). Negative ions only
(D). Positive hole charges

Ans: (B). Positive and negative ions

Explanation:
Chemical cells have two electrodes, which are strips of different materials, such as zinc and carbon. The electrodes are suspended in an electrolyte. This is a substance that contains free ions, which can carry electric current. ... Electrons flow through the electrolyte from the negative to positive electrode.

118. Which of the following primary cells has the lowest voltage?
(A). Lithium
(B). Zinc chloride
(C). Mercury
(D). Carbon zinc

Ans: (C). Mercury

119. Which of the following primary cells has the highest voltage ?
(A). Manganese-alkaline
(B). Carbon-zinc
(C). Lithium
(D). Mercury

Ans: (C). Lithium

120. Short-circuiting of a cell may be caused by
(A). Buckling of plates
(B). Faulty separators
(C). Lead particles forming circuit between positive and negative plates
(D). Any of the above

Ans: (D). Any of the above

Explanation:
buckling of plates. faulty separators. lead particles forming a circuit between positive and negative plates. excessive accumulation of sediment.

121. During electroplating the weight of substance deposited depends on

(A) quantity of electricity

(B) shape of the article

(C) room temperature

(D) atmospheric humidity.

Ans: (A) quantity of electricity

122. During electroplating, the amounts of different substances liberated by same quantity of electricity are proportional to their

(A) atomic weights

(B) atomic numbers

(C) chemical equivalents

(D) valency.

Ans: (C) chemical equivalents