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.

1.

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
Answer» E.
Discussion
2.

The specific gravity of electrolyte is measured by____________?
A. manometer
B. a mechanical gauge
C. hydrometer
D. psychrometer
Answer» D. psychrometer
Discussion
3.

The lead-acid cell should never be discharged beyond____________?
A. 1.8 V
B. 1.9 V
C. 2 V
D. 2.1 V
Answer» B. 1.9 V
Discussion
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
Answer» D. none of the above
Discussion
5.

48 ampere-hour capacity would deliver a current of___________?
A. 48 amperes for 1 hour
B. 24 amperes for 2 hours
C. 8 amperes for 6 hours
D. 6 amperes for 8 hours
Answer» E.
Discussion
6.

In alkaline cell the electrolyte is_____________?
A. dilute sulphuric acid
B. concentrated sulphuric acid
C. NaOH
D. KOH
Answer» E.
Discussion
7.

A typical output of a solar cell is_____________?
A. 0.1V
B. 0.26 V
C. 1.1 V
D. 2 V
Answer» C. 1.1 V
Discussion
8.

Which of the following factors adversely affects the capacity of the leadacid battery ?
A. Temperature of surroundings
B. Specific gravity of electrolyte
C. Rate of discharge
D. All of the above
Answer» E.
Discussion
9.

While preparing electrolyte for a lead-acid battery___________?
A. water is poured into acid
B. acid is poured into water
C. anyone of the two can be added to other chemical
Answer» C. anyone of the two can be added to other chemical
Discussion
10.

When two batteries are connected in parallel, it should be ensured that___________?
A. they have same e.m.f.
B. they have same make
C. they have same ampere-hour capacity
D. they have identical internal resistance
Answer» B. they have same make
Discussion
11.

Which of the following is incorrect ?
A. A storage cell has a reversible chemical reaction
B. A lead-acid cell can be recharged
C. A carbon-zinc cell has unlimited shelf life
D. A primary cell has an irreversible chemical reaction
Answer» D. A primary cell has an irreversible chemical reaction
Discussion
12.

Petroleum jelly is applied to the electrical connections to the lead-acid battery___________?
A. prevent local heating
B. prevent short-circuiting
C. reduce path resistance
D. prevent corrosion
Answer» E.
Discussion
13.

The common impurity in the electrolyte of lead-acid battery is_____________?
A. chlorine
B. dust particles
C. lead crystals
D. iron
Answer» E.
Discussion
14.

When the load resistance equals the generator resistance which of the following will be maximum __________?
A. Current
B. Efficiency of the circuit
C. Power in the load resistance
D. Voltage across the load resistance
Answer» D. Voltage across the load resistance
Discussion
15.

Which of the following cell has a. reversible chemical reaction ___________?
A. Lead-acid
B. Mercury oxide
C. Carbon-zinc
D. Silver-oxide
Answer» B. Mercury oxide
Discussion
16.

Which of the following has lower specific gravity V__________?
A. Dilute H2S04
B. Concentrated H2SO4
C. Water
D. Any of the above
Answer» D. Any of the above
Discussion
17.

In a battery cover is placed over the element and sealed to the top of the battery container. This is done____________?
A. to reduce evaporation of water from electrolyte
B. to exclude dirt and foreign matter from the electrolyte
C. to discharge both of the above functions
D. to discharge none of the above functions
Answer» D. to discharge none of the above functions
Discussion
18.

Hydrogen evolved during charging produces explosive mixture when it is more than___________?
A. 2%
B. 4%
C. 6%
D. 8%
Answer» E.
Discussion
19.

Which of the following battery is used for air-craft _____________?
A. Lead-acid battery
B. Nickel-iron battery
C. Dry cell battery
D. Silver oxide battery
Answer» C. Dry cell battery
Discussion
20.

A constant-voltage generator has___________?
A. minimum efficiency
B. minimum current capacity
C. low internal resistance
D. high internal resistance
Answer» D. high internal resistance
Discussion
21.

Which among the following constitutes the major load for an automobile battery _________?
A. Brake light
B. Self starter
C. Parking lights
D. Spark plugs
Answer» C. Parking lights
Discussion
22.

Satellite power requirement is provided through________?
A. solar cells
B. dry cells
C. nickel-cadmium cells
D. lead-acid batteries
Answer» B. dry cells
Discussion
23.

In a lead-acid battery the energy is stored in the form of___________?
A. charged ions
B. chemical energy
C. electrostatic energy
D. electromagnetic energy
Answer» C. electrostatic energy
Discussion
24.

Excessive formation of lead sulphate on the surface of the plates happens because of___________?
A. allowing a battery to stand in discharged condition for a long time
B. topping up with electrolyte
C. persistent undercharging
D. low level of electrolyte
E. all above
Answer» F.
Discussion
25.

Cells are connected in parallel to__________?
A. increase the efficiency
B. increase the current capacity
C. increase the voltage output
D. increase the internal resistance
Answer» C. increase the voltage output
Discussion
26.

The active materials on the positive and negative plates of a fully charged lead-acid battery are_______?
A. lead and lead peroxide
B. lead sulphate and lead
C. lead peroxide and lead
D. none of the above
Answer» D. none of the above
Discussion
27.

Under normal charging rate, the charging current should be__________?
A. 10% of capacity
B. 20% of capacity
C. 30% of capacity
D. 40% of capacity
Answer» B. 20% of capacity
Discussion
28.

During the charging of a lead-acid cell__________?
A. its voltage increases
B. it gives out energy
C. its cathode becomes dark chocolate brown in colour
D. specific gravity of H2SO4 decreases
Answer» B. it gives out energy
Discussion
29.

The substances which combine together to store electrical energy during the charge are called ________ materials
A. active
B. passive
C. inert
D. dielectric
Answer» B. passive
Discussion
30.

Undercharging___________?
A. reduces specific gravity of the electrolyte
B. increases specific gravity of the electrolyte
C. produces excessive gassing
D. increases the temperature
Answer» B. increases specific gravity of the electrolyte
Discussion
31.

In ________ system the charging current is intermittently controlled at either a maximum or minimum value
A. two rate charge control
B. trickle charge
C. floating charge
D. an equalizing charge
Answer» B. trickle charge
Discussion
32.

Over charging______________?
A. produces excessive gassing
B. loosens the active material
C. increases the temperature resulting in buckling of plates
D. all above
Answer» E.
Discussion
33.

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 above
Answer» E.
Discussion
34.

Electrolyte used in a lead-acid cell is__________?
A. NaOH
B. onlyH2S04
C. only water
D. dilute H2SO4
Answer» E.
Discussion
35.

The capacity of a lead-acid cell is measured in_____________?
A. amperes
B. ampere-hours
C. watts
D. watt-hours
Answer» C. watts
Discussion
36.

Internal short circuits are caused by___________?
A. breakdown of one or more separators
B. excess accumulation of sediment at the bottom of the cell
C. both (A) and (B)
D. none of the above
Answer» D. none of the above
Discussion
37.

Lead-acid cell has a life of nearly charges and discharges______________?
A. 500
B. 700
C. 1000
D. 1250
Answer» E.
Discussion
38.

If a lead-acid cell is discharged below 1.8 V the following will happen.____________?
A. Capacity of cell will reduce
B. Sulphation of plates will occur
C. Internal resistance will increase
D. All above will occur
Answer» E.
Discussion
39.

Internal resistance of a cell is due to___________?
A. resistance of electrolyte
B. electrode resistance
C. surface contact resistance between electrode and electrolyte
D. all above
Answer» E.
Discussion
40.

During discharge, the active material of both the positive and negative plates is changed to___________?
A. Pb
B. Pb02
C. PbO
D. PbS04
Answer» E.
Discussion
41.

Level of electrolyte in a cell should be ________ the level of plates
A. below
B. equal to
C. above
D. none of the above
Answer» D. none of the above
Discussion
42.

Shelf life of a small dry cell is___________?
A. equal to that of large dry cell
B. less than that of large dry cell
C. more than that of large dry cell
D. none of the above
Answer» C. more than that of large dry cell
Discussion
43.

If a battery is wrongly connected on charge following will happen__________?
A. current delivered by the battery will be high
B. current drawing will be nil
C. current drawing will be very small
D. current drawing will be very high
Answer» E.
Discussion
44.

Persons preparing electrolyte should wear___________?
A. goggles or other face shield
B. rubber
C. rubber boots and gloves
D. all above safety devices
Answer» E.
Discussion
45.

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
Answer» E.
Discussion
46.

The current flow through electrolyte is due to the movement of____________?
A. ions
B. holes
C. electrons
D. none of the above
Answer» B. holes
Discussion
47.

Life of the batteries is in the following ascending order____________?
A. Lead-acid cell, Edison cell, Nickel cadmium cell
B. Lead-acid cell, Nickel-cadmium cell, Edison cell
C. Edison cell, Nickel-cadmium cell, lead-acid cell
D. Nickel-cadmium cell, Edison cell, lead-acid cell
Answer» B. Lead-acid cell, Nickel-cadmium cell, Edison cell
Discussion
48.

______ of electrolyte indicates the state of charge of the battery
A. colour
B. mass
C. viscosity
D. specific gravity
Answer» E.
Discussion
49.

Batteries are charged by_____________?
A. rectifiers
B. engine generator sets
C. motor generator sets
D. any one of the above methods
Answer» E.
Discussion
50.

In a lead-acid cell, lead is called as____________?
A. positive active material
B. negative active material
C. passive material
D. none of the above
Answer» C. passive material
Discussion