Explore topic-wise MCQs in Electrical Engineering Questions.

This section includes 119 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.

51.

Following will happen if the specific gravity of electrolyte becomes more than 1.23
A. Loss of capacity
B. Loss of life
C. Corrosion of the grids of the plate
D. All above
Answer» E.
Discussion
52.

In constant-current charging method, the supply voltage from discharged to fully charged condition____________?
A. decreases
B. increases
C. remains constant
D. none of the above
Answer» C. remains constant
Discussion
53.

On overcharging a battery____________?
A. it will bring about chemical change in active 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 will occur
Answer» E.
Discussion
54.

Following will occur if level of electrolyte falls below plates____________?
A. capacity of the cell is reduced
B. life of the cell is reduced
C. open plates are converted to lead sulphate
D. all above
Answer» E.
Discussion
55.

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
Answer» E.
Discussion
56.

In constant voltage charging method, the charging current from discharged to fully charged condition_____________?
A. decreases
B. increases
C. remains constant
D. none of the above
Answer» B. increases
Discussion
57.

The effect of sulphation is that the internal resistance__________?
A. increases
B. decreases
C. remains same
D. none of the above
Answer» B. decreases
Discussion
58.

Following will happen if battery charging rate is too high______________?
A. excessive gassing will occur
B. temperature rise will occur
C. bulging and buckling of plates will occur
D. all above will occur
Answer» E.
Discussion
59.

Cell short circuit results in_________?
A. low sp. gravity electrolyte
B. abnormal high temperature
C. reduced gassing on charge
D. all above
Answer» E.
Discussion
60.

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
A. 6 parts of acid to 4 parts of water
B. 4 parts of acid to 4 parts of water
C. 4 parts of acid to 6 parts of water
D. 4 parts of acid to 8 parts of water
Answer» D. 4 parts of acid to 8 parts of water
Discussion
61.

Battery container should be acid resistance, therefore it is made up of___________?
A. glass
B. plastic
C. wood
D. all above
Answer» E.
Discussion
62.

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 cell is on open circuit
C. both A. and (b)
D. none of the above
Answer» E.
Discussion
63.

Capacity of dry cells is_________?
A. more when it is supplying current for intermittent periods
B. more when it is supplying current for continuous periods
C. unaffected by the type of discharge
D. none of the above
Answer» B. more when it is supplying current for continuous periods
Discussion
64.

Sulphated cells are indicated by____________?
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
Answer» E.
Discussion
65.

Internal resistance of a cell is reduced by__________?
A. using vent plug to permit gas formed during discharge
B. increasing the plate area
C. putting plates very close together
D. all above methods
Answer» E.
Discussion
66.

Those substances of the cell which take active part in chemical combination and hence produce electricity during charging or discharging are known as________materials
A. passive
B. active
C. redundant
D. inert
Answer» C. redundant
Discussion
67.

The best indication about the state of charge on a lead-acid battery is given by____________?
A. output voltage
B. temperature of electrolyte
C. specific gravity of electrolyte
D. none of the above
Answer» D. none of the above
Discussion
68.

During the charging and discharging of a nickel-iron cell____________?
A. corrosive fumes are produced
B. water is neither formed nor absorbed
C. nickel hydroxide remains unsplit
D. its e.m.f. remains constant
Answer» C. nickel hydroxide remains unsplit
Discussion
69.

Extent of corrosion in the underground metal work depends upon___________?
A. amount of moisture
B. type of metals
C. type of soil chemicals
D. all above factors
Answer» E.
Discussion
70.

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
Answer» D. none of the above
Discussion
71.

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
Answer» E.
Discussion
72.

The body of Edison cell is made of___________?
A. bakelite
B. rubber
C. nickel plated steel
D. aluminium
Answer» D. aluminium
Discussion
73.

As compared to constant-current system, the constant-voltage system of charging a lead acid cell has the advantage of___________?
A. reducing time of charging
B. increasing cell capacity
C. both (A) and (B)
D. avoiding excessive gassing
Answer» D. avoiding excessive gassing
Discussion
74.

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
Answer» B. increase the current rating
Discussion
75.

Specific gravity of electrolyte in Edison cell is_____________?
A. 0.8
B. 0.95
C. 1.1
D. 1.21
Answer» E.
Discussion
76.

The output voltage of a charger is__________?
A. less than the battery voltage
B. higher than the battery voltage
C. the same as the battery voltage
D. none of the above
Answer» C. the same as the battery voltage
Discussion
77.

Which of the following primary cells has the highest voltage___________ ?
A. Manganese-alkaline
B. Carbon-zinc
C. Lithium
D. Mercury
Answer» D. Mercury
Discussion
78.

During the idle period of the battery, strong electrolyte tends to change the active material of the cell into____________?
A. Pb02
B. PbSC-4
C. PbO
D. Pb
Answer» C. PbO
Discussion
79.

All the electrical connections between the battery and vehicle should be by____________?
A. thin aluminium wires
B. thin copper wires
C. rigid cables
D. flexible cables
Answer» E.
Discussion
80.

Ampere hour capacity of an industrial battery is based on _______ hours discharge rate
A. 8
B. 12
C. 16
D. 24
Answer» B. 12
Discussion
81.

The watt-hour efficiency of a lead-acid cell varies between________?
A. 25 to 35%
B. 40 to 60%
C. 70 to 80%
D. 90 to 95%
Answer» D. 90 to 95%
Discussion
82.

Self charge of a Ni-Fe cell is _______ Edison cell
A. equal to
B. less than
C. more than
D. much more than
Answer» C. more than
Discussion
83.

For a cell to work, which of the following condition(s) become necessary ___________?
A. Two electrodes of different meta’s should be inserted in the electrolyte, not touching each other
B. Electrolyte must chemically react with one of the electrodes
C. Electrolyte liquid or paste should be conducting
D. All above three conditions are necessary
Answer» E.
Discussion
84.

Mercury cell has which of the following characteristics ____________?
A. Flat discharge current-voltage curve
B. High power to weight ratio
C. Comparatively longer shelf life under adverse conditions of high temperature and humidity
D. All of the above
Answer» E.
Discussion
85.

Charging a sulphated battery at high rate results in___________?
A. boiling of electrolyte due to gassing
B. warping of plates
C. damage to separators, cell caps covers and battery case due to excessive temperature
D. all above
Answer» E.
Discussion
86.

Which of the following primary cells has the lowest voltage_________ ?
A. Lithium
B. Zinc-chloride
C. Mercury
D. Carbon-zinc
Answer» D. Carbon-zinc
Discussion
87.

Short circuiting of a cell may be caused____________?
A. buckling of plates
B. faulty separators
C. lead particles forming circuit between positive and negative plates
D. excessive accumulation of sediment
E. any one of above
Answer» F.
Discussion
88.

The active material of the positive plates of silver-zinc batteries is_________?
A. silver oxide
B. lead oxide
C. lead
D. zinc powder
Answer» B. lead oxide
Discussion
89.

The ampere-hour efficiency of a lead acid cell is normally between_________?
A. 20 to 30%
B. 40 to 50%
C. 60 to 70%
D. 90 to 95%
Answer» E.
Discussion
90.

Charging of sulfated battery produces _________ heat
A. no
B. very little
C. less
D. more
Answer» E.
Discussion
91.

When the lead-acid cell is fully charged, the electrolyte assumes _______ appearance
A. dull
B. reddish
C. bright
D. milky
Answer» E.
Discussion
92.

The average charging voltage for alkali cell is about__________?
A. 1 V
B. 1.2 V
C. 1.7 V
D. 2.1 V
Answer» D. 2.1 V
Discussion
93.

Trickle charging of a storage battery helps to___________?
A. maintain proper electrolyte level
B. increase its reserve capacity
C. prevent sulphation
D. keep it fresh and fully charged
Answer» E.
Discussion
94.

When the specific gravity of the electrolyte of a lead-acid cell is reduced to 1.1 to 1.15 the cell is in___________?
A. charged state
B. discharged state
C. both (A) and (B)
D. active state
Answer» C. both (A) and (B)
Discussion
95.

Electrolyte used in an Edison cell is___________?
A. NaOH
B. KOH
C. HC1
D. HN03
Answer» C. HC1
Discussion
96.

Negative plate of an Edison cell is made of__________?
A. copper
B. lead
C. iron
D. silver oxide
Answer» D. silver oxide
Discussion
97.

It is noticed that durum charging___________?
A. there is a rise in voltage
B. energy is absorbed by the cell
C. specific gravity of H2SO4 is increased
D. the anode becomes chocolate brown in colour (PbCfe) and cathode becomes grey metallic lead (Pb)
E. all of the above
Answer» F.
Discussion
98.

Life of the Edison cell is at least_____________?
A. five years
B. seven years
C. eight years
D. ten years
Answer» B. seven years
Discussion
99.

On the average the ampere-hour efficiency of an Edison cell is about__________?
A. 40%
B. 60%
C. 70%
D. 80%
Answer» E.
Discussion
100.

The capacity of a lead-acid cell does not depend on its___________?
A. temperature
B. rate of charge
C. rate of discharge
D. quantity of active material
Answer» C. rate of discharge
Discussion