electrolysis and storage of batteries MCQs – Page 2

Practise focused electrolysis and storage of batteries questions with marked answers for exam preparation and subject revision.

electrolysis and storage of batteries Mcqs
51. 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
52. 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

53. The e.m.f. of an Edison cell, when fully charged, is nearly______________?
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A. 1.4 V

B. 1 V

C. 0.9 V

D. 0.8 V

54. Electrolyte used in a lead-acid cell is__________?
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A. NaOH

B. onlyH2S04

C. only water

D. dilute H2SO4
55. Internal resistance of a cell is reduced by__________?
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A. all above methods

B. putting plates very close together

C. using vent plug to permit gas formed during discharge

D. increasing the plate area

56. Following will occur if level of electrolyte falls below plates____________?
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A. life of the cell is reduced

B. all above

C. open plates are converted to lead sulphate

D. capacity of the cell is reduced

57. 48 ampere-hour capacity would deliver a current of___________?
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A. 6 amperes for 8 hours

B. 48 amperes for 1 hour

C. 8 amperes for 6 hours

D. 24 amperes for 2 hours

58. The output voltage of a charger is__________?
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A. less than the battery voltage

B. the same as the battery voltage

C. higher than the battery voltage

D. none of the above

59. Self charge of a Ni-Fe cell is _______ Edison cell
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A. much more than

B. more than

C. less than

D. equal to

60. Excessive charging a battery tends to____________?
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A. to corrode the positive plates into lead peroxide thereby weakening them physically

B. produce gassing

C. bring about all above changes

D. increase the internal resistance of the battery

61. When the specific gravity of the electrolyte of a lead-acid cell is reduced to 1.1 to 1.15 the cell is in___________?
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A. charged state

B. discharged state

C. both (A) and (B)

D. active state

62. The capacity of a lead-acid cell depends on
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A. rate of discharge

B. all above

C. temperature

D. density of electrolyte

E. quantity of active materials

63. Cells are connected in parallel to__________?
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A. increase the current capacity

B. increase the efficiency

C. increase the voltage output

D. increase the internal resistance

64. In order that a hydrometer may float vertically in electrolyte its C.G. should be___________?
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A. displaced sideways

B. raised

C. lowered

D. undisturbed

65. The ratio of ampere-hour efficiency to watt-hour efficiency of a lead-acid cell is____________?
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A. always less than one

B. none of the above

C. just one

D. always greater than one
66. The body of Edison cell is made of___________?
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A. aluminium

B. nickel plated steel

C. rubber

D. bakelite

67. Under normal charging rate, the charging current should be__________?
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A. 10% of capacity

B. 40% of capacity

C. 30% of capacity

D. 20% of capacity

68. The active materials of a nickel-iron battery are___________?
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A. nickel hydroxide

B. 21% solution of KOH

C. all of the above

D. powdered iron and its oxide

69. Life of the Edison cell is at least_____________?
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A. eight years

B. ten years

C. five years

D. seven years

70. In ________ system the charging current is intermittently controlled at either a maximum or minimum value
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A. an equalizing charge

B. floating charge

C. trickle charge

D. two rate charge control
71. Which of the following has lower specific gravity V__________?
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A. Water

B. Any of the above

C. Concentrated H2SO4

D. Dilute H2S04

72. During charging the specific gravity of the electrolyte of a lead-acid battery
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A. increases

B. remains the same

C. becomes zero

D. decreases

73. During discharge, the active material of both the positive and negative plates is changed to___________?
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A. PbO

B. Pb

C. Pb02

D. PbS04
74. Petroleum jelly is applied to the electrical connections to the lead-acid battery___________?
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A. reduce path resistance

B. prevent short-circuiting

C. prevent corrosion

D. prevent local heating

75. The capacity of a lead-acid cell is measured in_____________?
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A. ampere-hours

B. watt-hours

C. watts

D. amperes

76. Mercury cell has which of the following characteristics ____________?
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A. All of the above

B. Comparatively longer shelf life under adverse conditions of high temperature and humidity

C. High power to weight ratio

D. Flat discharge current-voltage curve

77. Persons preparing electrolyte should wear___________?
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A. rubber boots and gloves

B. rubber

C. all above safety devices

D. goggles or other face shield

78. The best indication about the state of charge on a lead-acid battery is given by____________?
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A. none of the above

B. specific gravity of electrolyte

C. temperature of electrolyte

D. output voltage

79. Local action in a battery is indicated by____________?
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A. excessive gassing under load conditions

B. excessive drop in the specific gravity of electrolyte even when the cell is on open circuit

C. both A. and (b)

D. none of the above
80. Lead-acid cell has a life of nearly charges and discharges______________?
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A. 1250

B. 700

C. 500

D. 1000

81. Hydrogen evolved during charging produces explosive mixture when it is more than___________?
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A. 4%

B. 8%

C. 6%

D. 2%

82. Which of the following battery is used for air-craft _____________?
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A. Nickel-iron battery

B. Lead-acid battery

C. Dry cell battery

D. Silver oxide battery

83. Dry cell is modification of____________?
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A. Edison cell

B. Lead-acid cell

C. Deniell cell

D. Leclanche cell
84. In constant voltage charging method, the charging current from discharged to fully charged condition_____________?
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A. decreases

B. remains constant

C. none of the above

D. increases

85. The internal resistance of an alkali cell is nearly _________ times that of the lead-acid cell
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A. four

B. two

C. five

D. three

86. Negative plate of an Edison cell is made of__________?
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A. silver oxide

B. copper

C. iron

D. lead

87. All the electrical connections between the battery and vehicle should be by____________?
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A. flexible cables

B. thin copper wires

C. rigid cables

D. thin aluminium wires

88. Internal resistance of a cell is due to___________?
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A. surface contact resistance between electrode and electrolyte

B. resistance of electrolyte

C. all above

D. electrode resistance

89. Short circuiting of a cell may be caused____________?
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A. faulty separators

B. excessive accumulation of sediment

C. buckling of plates

D. any one of above

E. lead particles forming circuit between positive and negative plates

90. Which of the following primary cells has the highest voltage___________ ?
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A. Lithium

B. Manganese-alkaline

C. Mercury

D. Carbon-zinc

91. The average charging voltage for alkali cell is about__________?
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A. 1.2 V

B. 2.1 V

C. 1 V

D. 1.7 V
92. The watt-hour efficiency of a lead-acid cell varies between________?
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A. 90 to 95%

B. 25 to 35%

C. 40 to 60%

D. 70 to 80%
93. Weston standard cell at 20C has voltage of _______ volts
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A. 0.8

B. 1.5

C. 1.0187

D. 0.9

94. As compared to constant-current system, the constant-voltage system of charging a lead acid cell has the advantage of___________?
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A. reducing time of charging

B. increasing cell capacity

C. both (A) and (B)

D. avoiding excessive gassing

95. The charge required to liberate one gram equivalent of any substance is known as _________ constant
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A. Boltzman

B. Faradays

C. time

96. Over charging______________?
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A. all above

B. increases the temperature resulting in buckling of plates

C. produces excessive gassing

D. loosens the active material

97. The active material of the positive plates of silver-zinc batteries is_________?
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A. lead oxide

B. zinc powder

C. lead

D. silver oxide
98. Extent of corrosion in the underground metal work depends upon___________?
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A. type of metals

B. type of soil chemicals

C. all above factors

D. amount of moisture

99. The following indicate that battery on charge has attained full charge___________?
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A. all above

B. colour of electrode

C. gassing

D. specific gravity

100. Following will happen if battery charging rate is too high______________?
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A. temperature rise will occur

B. bulging and buckling of plates will occur

C. excessive gassing will occur

D. all above will occur