Top Most Electrolysis & Storage Of Batteries Objective Questions
1.When a lead-acid battery is in fully charged condition, the colour of its positive plate is
dark grey
brown
dark brown
none of above
ANSWER : : dark brown
2.Those substances of the cell which take active part in chemical combination and hence produce electricity during charging or discharging are known as______materials.
passive
active
redundant
inert
ANSWER : : active
3.Cells are connected in series in order to
increase the voltage rating
increase the current rating
increase the life of the cells
none of the above
ANSWER : : increase the voltage rating
4.During the charging of a lead-acid cell
its voltage increases
it gives out energy
its cathode becomes dark chocolate brown in colour
specific gravity of H2SO4 decreases
ANSWER : : its voltage increases
5.A dead storage battery can be revived by
adding distilled water
adding so-called battery restorer
a dose of H2SO4
none of the above
ANSWER : : none of the above
6.The ratio of ampere-hour efficiency to watt-hour efficiency of a lead-acid cell is
just one
always greater than one
always less than one
none of the above.
ANSWER : : always greater than one
7.The ampere-hour efficiency of a leadacid cell is normally between
20 to 30%
40 to 50%
60 to 70%
90 to 95%
ANSWER : s: d
8.In a lead-acid cell dilute sulphuric acid (electrolyte) approximately comprises the following
one part H2O, three parts H2SO4
two parts H2O, two parts H2SO4
three parts H2O, one part H2SO4
all H2S04
ANSWER : : three parts H2O, one part H2SO4
9.Duringthe charging and discharging of a nickel-iron cell
corrosive fumes are produced
water is neither formed nor absorbed
nickel hydroxide remains unsplit
its e.m.f. remains constant
ANSWER : : water is neither formed nor absorbed
10.It is noticed that during discharging the following does not happen
both anode and cathode become PbS04
specific gravity of H2SO4 decreases
voltage of the cell decreases
the cell absorbs energy
ANSWER : : the cell absorbs energy
11.The capacity of a lead-acid cell does not depend on its
temperature
rate of charge
rate of discharge
quantity of active material
ANSWER : : rate of charge
12.As compared to constant-current system, the constant-voltage system of charging a lead acid cell has the advantage of
reducing time of charging
increasing cell capacity
both (a) and (b)
avoiding excessive gassing
ANSWER : : both (a) and (b)
13.The storage battery generally used in electric power station is
nickel-cadmium battery
zinc-carbon battery
lead-acid battery
none of the above
ANSWER : : lead-acid battery
14.The active materials on the positive and negative plates of a fully charged lead-acid battery are
lead and lead peroxide
lead sulphate and lead
lead peroxide and lead
none of the above
ANSWER : : lead peroxide and lead
15.During charging the specific gravity of the electrolyte of a lead-acid battery
increases
decreases
remains the same
becomes zero
ANSWER : : increases
16.The capacity of a battery is expressed in terms of
current rating
voltage rating
ampere-hour rating
none of the above
ANSWER : : ampere-hour rating
17.Trickle charging of a storage battery helps to
maintain proper electrolyte level
increase its reserve capacity
prevent sulphation
keep it fresh and fully charged
ANSWER : : keep it fresh and fully charged
18.As compared to a lead-acid cell, the efficiency of a nickel-iron cell is less due to its
compactness
lower e.m.f.
small quantity of electrolyte used
higher internal resistance
ANSWER : : higher internal resistance
19.The active materials of a nickel-iron battery are
nickel hydroxide
powdered iron and its oxide
21% solution of KOH
all of the above
ANSWER : : all of the above
20.When the lead-acid cell is fully charged, the electrolyte assumes _____ appearance
dull
reddish
bright
milky
ANSWER : : milky
21.The output voltage of a charger is
less than the battery voltage
higher than the battery voltage
the same as the battery voltage
none of the above
ANSWER : : higher than the battery voltage
22.Five 2 V cells are connected in parallel. The output voltage is
1 V
1.5 V
1.75 V
2 V
ANSWER : : 2 V
23.The capacity of a lead-acid cell is measured in
amperes
ampere-hours
watts
watt-hours
ANSWER : : ampere-hours
24.The watt-hour efficiency of a lead-acid cell varies between
25 to 35%
40 to 60%
70 to 80%
90 to 95%
ANSWER : : 70 to 80%
25.The best indication about the state of charge on a lead-acid battery is given by
output voltage
temperature of electrolyte
specific gravity of electrolyte
none of the above
ANSWER : : specific gravity of electrolyte
26.On overcharging a battery
it will bring about chemical change in active materials
it will increase the capacity of the battery
it will raise the specific gravity of the electrolyte
none of the above will occur
ANSWER : : none of the above will occur
27.Electrolyte used in a lead-acid cell is
NaOH
onlyH2S04
only water
dilute H2SO4
ANSWER : : dilute H2SO4
28.In ______ system the charging current is intermittently controlled at either a maximum or minimum value
two rate charge control
trickle charge
floating charge
an equalizing charge
ANSWER : : two rate charge control
29.The active material of the positive plates of silver-zinc batteries is
silver oxide
lead oxide
lead
zinc powder
ANSWER : : silver oxide
30.When the specific gravity of the electrolyte of a lead-acid cell is reduced to 1.1 to 1.15 the cell is in
charged state
discharged state
both (a) and (b)
active state
ANSWER : : discharged state
31.The internal resistance of an alkali cell is nearly _____ times that of the lead-acid cell.
two
three
four
five
ANSWER : : five
32.The effect of sulphation is that the internal resistance
increases
decreases
remains same
none of the above
ANSWER : : increases
33.The specific gravity of electrolyte is measured by
manometer
a mechanical gauge
hydrometer
psychrometer
ANSWER : : hydrometer
34.The average charging voltage for alkali cell is about
1 V
1.2 V
1.7 V
2.1 V
ANSWER : : 1.7 V
35.The internal resistance of a lead-acid cell is _____ that of Edison cell
less than
more than
equal to
none of the above
ANSWER : : less than
36.Life of the Edison cell is at least
five years
seven years
eight years
ten years
ANSWER : : five years
37.Lead-acid cell has a life of nearly charges and discharges
500
700
1000
1250
ANSWER : : 1250
38.Each cell has a vent cap
to allow gases out when the cell is on charge
to add water to the cell if needed
to check the level of electrolyte
to do all above functions
ANSWER : : to do all above functions
39.The open circuit voltage of any storage cell depends wholly upon
its chemical constituents
on the strength of its electrolyte
its temperature
all above
ANSWER : : all above
40.In a lead-acid cell, lead is called as
positive active material
negative active material
passive material
none of the above
ANSWER : : negative active material
41.The substances which combine together to store electrical energy during the charge are called ______ materials
active
passive
inert
dielectric
ANSWER : : active
42.On the average the ampere-hour efficiency of an Edison cell is about
40%
60%
70%
80%
ANSWER : : 80%
43.Negative plate of an Edison cell is made of
copper
lead
iron
silver oxide
ANSWER : : iron
44.Over charging
produces excessive gassing
loosens the active material
increases the temperature resulting in buckling of plates
all above
ANSWER : : all above
45.Internal short circuits are caused by
breakdown of one or more separators
excess accumulation of sediment at the bottom of the cell
both (a) and (b)
none of the above
ANSWER : : both (a) and (b)
46.Electrolyte used in an Edison cell is
NaOH
KOH
HC1
HN03
ANSWER : : KOH
47.Excessive formation of lead sulphate on the surface of the plates happens because of
allowing a battery to stand in discharged condition for a long time
topping up with electrolyte
persistent undercharging
low level of electrolyte
ANSWER : : all above
48.The lead-acid cell should never be discharged beyond
1.8 V
1.9 V
2 V
2.1 V
ANSWER : : 1.8 V
49.Undercharging
reduces specific gravity of the electrolyte
increases specific gravity of the electrolyte
produces excessive gassing
increases the temperature
ANSWER : : reduces specific gravity of the electrolyte
50.If a battery is wrongly connected on charge following will happen
current delivered by the battery will be high
current drawing will be nil
current drawing will be very small
current drawing will be very high
ANSWER : : current drawing will be very high
51.48 ampere-hour capacity would deliver a current of
48 amperes for 1 hour
24 amperes for 2 hours
8 amperes for 6 hours
6 amperes for 8 hours
ANSWER : : 6 amperes for 8 hours
52.Battery charging equipment is generally installed
in well ventilated location
in clean and dry place
as near as practical to the battery being charged
in location having all above features
ANSWER : : in location having all above features
53.In constant-current charging method, the supply voltage from discharged to fully charged condition
decreases
increases
remains constant
none of the above
ANSWER : : increases
54.Sulphated cells are indicated by
the loss of capacity of the cell
the decrease of the specific gravity
the low voltage of the cell on discharge
all above conditions
ANSWER : : all above conditions
55.Life of the batteries is in the following ascending order.
Lead-acid cell, Edison cell, Nickel cadmium cell
Lead-acid cell, Nickel-cadmium cell, Edison cell
Edison cell, Nickel-cadmium cell, lead-acid cell
Nickel-cadmium cell, Edison cell, lead-acid cell
ANSWER : : Lead-acid cell, Edison cell, Nickel cadmium cell
56.In order that a hydrometer may float vertically in electrolyte its C.G. should be
lowered
raised
undisturbed
displaced sideways
ANSWER : : lowered
57.Battery container should be acid resistance, therefore it is made up of
glass
plastic
wood
all above
ANSWER : : all above
58.Local action in a battery is indicated by
excessive gassing under load conditions
excessive drop in the specific gravity of electrolyte even when the cell is on open circuit
both (a) and (b)
none of the above
ANSWER : : none of the above
59.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
6 parts of acid to 4 parts of water
4 parts of acid to 4 parts of water
4 parts of acid to 6 parts of water
4 parts of acid to 8 parts of water
ANSWER : : 4 parts of acid to 6 parts of water
60.Level of electrolyte in a cell should be _____ the level of plates
below
equal to
above
none of the above
ANSWER : : above
61.Batteries are charged by
rectifiers
engine generator sets
motor generator sets
any one of the above methods
ANSWER : s: d
62.Excessive charging a battery tends to
produce gassing
increase the internal resistance of the battery
to corrode the positive plates into lead peroxide thereby weakening them physically
bring about all above changes
ANSWER : : bring about all above changes
63.Capacity of dry cells is
more when it is supplying current for intermittent periods
more when it is supplying current for continuous periods
unaffected by the type of discharge
none of the above
ANSWER : : more when it is supplying current for intermittent periods
64.Cell short circuit results in
low sp. gravity electrolyte
abnormal high temperature
reduced gassing on charge
all above
ANSWER : : all above
65.Shelf life of a small dry cell is
equal to that of large dry cell
less than that of large dry cell
more than that of large dry cell
none of the above
ANSWER : : less than that of large dry cell
66.If a lead-acid cell is discharged below 1.8 V the following will happen.
Capacity of cell will reduce
Sulphation of plates will occur
Internal resistance will increase
All above will occur
ANSWER : : All above will occur
67.Persons preparing electrolyte should wear
goggles or other face shield
rubber
rubber boots and gloves
all above safety devices
ANSWER : : all above safety devices
68.During discharge, the active material of both the positive and negative plates is changed to
Pb
Pb02
PbO
PbS04
ANSWER : : PbS04
69.Internal resistance of a cell is reduced by
using vent plug to permit gas formed during discharge
increasing the plate area
putting plates very close together
all above methods
ANSWER : : all above methods
70.In constant voltage charging method, the charging current from discharged to fully charged condition
decreases
increases
remains constant
none of the above
ANSWER : : decreases
71.The current flow through electrolyte is due to the movement of
ions
holes
electrons
none of the above
ANSWER : : ions
72.Internal resistance of a cell is due to
resistance of electrolyte
electrode resistance
surface contact resistance between electrode and electrolyte
all above
ANSWER : : all above
73.Following will happen if the specific gravity of electrolyte becomes more than 1.23.
Loss of capacity
Loss of life
Corrosion of the grids of the plate
All above
ANSWER : : All above
74.Following will happen if battery charging rate is too high
excessive gassing will occur
temperature rise will occur
bulging and buckling of plates will occur
all above will occur
ANSWER : : all above will occur
75.Ampere hour capacity of an industrial battery is based on ____ hours discharge rate.
8
12
16
24
ANSWER : : 8
76.A battery of 6 cells will show a drop of _____ volts from fully charged state to fully discharged state.
1.0
1.5
2.4
2.9
ANSWER : : 2.4
77.Weston standard cell at 20�C has voltage of ____ volts.
0.8
0.9
1.0187
1.5
ANSWER : : 1.0187
78.All the electrical connections between the battery and vehicle should be by
thin aluminium wires
thin copper wires
rigid cables
flexible cables
ANSWER : : flexible cables
79.The following indicate that battery on charge has attained full charge
colour of electrode
gassing
specific gravity
all above
ANSWER : : all above
80.The body of Edison cell is made of
bakelite
rubber
nickel plated steel
aluminium
ANSWER : : nickel plated steel
81.Extent of corrosion in the underground metal work depends upon
amount of moisture
type of metals
type of soil chemicals
all above factors
ANSWER : : all above factors
82.Which of the following primary cells has the highest voltage ?
Manganese-alkaline
Carbon-zinc
Lithium
Mercury
ANSWER : : Lithium
83.Short circuiting of a cell may be caused
buckling of plates
faulty separators
lead particles forming circuit between positive and negative plates
excessive accumulation of sediment
ANSWER : : any one of above
84.Charging a sulphated battery at high rate results in
boiling of electrolyte due to gassing
warping of plates
damage to separators, cell caps covers and battery case due to ex�cessive temperature
all above
ANSWER : : all above
85.During the idle period of the battery, strong electrolyte tends to change the active material of the cell into
Pb02
PbSC-4
PbO
Pb
ANSWER : : PbSC-4
86.In a battery cover is placed over the element and sealed to the top of the battery container. This is done
to reduce evaporation of water from electrolyte
to exclude dirt and foreign matter from the electrolyte
to discharge both of the above functions
to discharge none of the above functions
ANSWER : : to discharge both of the above functions
87.Capacity of a battery.is expressed in
Ah
Vh
Wh
kWh
ANSWER : : Ah
88.Which of the following primary cells has the lowest voltage ?
Lithium
Zinc-chloride
Mercury
Carbon-zinc
ANSWER : : Mercury
89.Specific gravity of electrolyte in Edison cell is
0.8
0.95
1.1
1.21
ANSWER : : 1.21
90.Which of the following cell has a. reversible chemical reaction ?
Lead-acid
Mercury oxide
Carbon-zinc
Silver-oxide
ANSWER : : Lead-acid
91.Dry cell is modification of
Deniell cell
Leclanche cell
Lead-acid cell
Edison cell
ANSWER : : Leclanche cell
92.While preparing electrolyte for a lead-acid battery
water is poured into acid
acid is poured into water
anyone of the two can be added to other chemical
acid is poured into water
ANSWER : hich of the following battery is used for air-craft ?
93.Mercury cell has which of the following characteristics ?
Flat discharge current-voltage curve
High power to weight ratio
Comparatively longer shelf life under adverse conditions of high temperature and humidity
All of the above
ANSWER : : All of the above
94.In alkaline cell the electrolyte is
dilute sulphuric acid
concentrated sulphuric acid
NaOH
KOH
ANSWER : : KOH
95.Self charge of a Ni-Fe cell is _____ Edison cell.
equal to
less than
more than
much more than
ANSWER : : less than
96.For a cell to work, which of the following condition(s) become necessary ?
Two electrodes of different meta’s should be inserted in the electrolyte, not touching each other
Electrolyte must chemically react with one of the electrodes
Electrolyte liquid or paste should be conducting
All above three conditions are necessary
ANSWER : : All above three conditions are necessary
97.Chargmg of sulphated battery produces ____ heat.
no
very little
less
more
ANSWER : : more
98.Hydrogen evolved during charging produces explosive mixture when it is more than
2%
4%
6%
8%
ANSWER : : 8%
99.In a lead-acid battery the energy is stored in the form of
charged ions
chemical energy
electrostatic energy
electromagnetic energy
ANSWER : : chemical energy
100.Which of the following has lower sp. gravity V
Dilute H2S04
Concentrated H2SO4
Water
Any of the above
ANSWER : : Water
101.Satellite power requirement is provided through
solar cells
dry cells
nickel-cadmium cells
lead-acid batteries
ANSWER : : solar cells
102.Petroleum jelly is applied to the electrical connections to the lead-acid battery
prevent local heating
prevent short-circuiting
reduce path resistance
prevent corrosion
ANSWER : : prevent corrosion
103.A typical output of a solar cell is
0.1V
0.26 V
1.1 V
2 V
ANSWER : : 0.26 V
104.Under normal charging rate, the charging current should be
10% of capacity
20% of capacity
30% of capacity
40% of capacity
ANSWER : : 10% of capacity
105.Cells are connected in parallel to
increase the efficiency
increase the current capacity
increase the voltage output
increase the internal resistance
ANSWER : : increase the current capacity
106.When two batteries are connected in parallel, it should be ensured that
they have same e.m.f.
they have same make
they have same ampere-hour capa-city
they have identical internal resistance
ANSWER : : they have same e.m.f.
107.A constant-voltage generator has
minimum efficiency
minimum current capacity
low internal resistance
high internal resistance
ANSWER : : low internal resistance
108.Which among the following constitutes the major load for an automobile battery ?
Brake light
Self starter
Parking lights
Spark plugs
ANSWER : : Self starter
109.When the load resistance equals the generator resistance which of the following will be maximum ?
Current
Efficiency of the circuit
Power in the load resistance
Voltage across the load resistance
ANSWER : : Power in the load resistance
110.The common impurity in the electrolyte of lead-acid battery is
chlorine
dust particles
lead crystals
iron
ANSWER : : iron
111.Which of the following factors adversely affects the capacity of the leadacid battery ?
Temperature of surroundings
Specific gravity of electrolyte
Rate of discharge
All of the above
ANSWER : : All of the above