Explore topic-wise MCQs in Electrical Engineering Questions.

This section includes 50 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.

Induction heating takes place it which of the following ?
A. Insulating materials
B. Conducting materials which are magnetic
C. Conducting materials which are non-magnetic
D. Conducting materials which may or may not be magnetic
Answer» E.
Discussion
2.

The material of the heating element for a furnace should have___________?
A. lower melting point
B. higher temperature coefficient
C. high specific resistance
D. all of the above
Answer» D. all of the above
Discussion
3.

When a body reflects entire radiation incident on it, then it is known as____________?
A. white body
B. grey body
C. black body
D. transparent body
Answer» B. grey body
Discussion
4.

Properly of low temperature co-eflficient of heating element is desired due to which of the following reasons ?
A. To avoid initial rush of current
B. To avoid change in kW rating with temperature
C. Both (A) and (B)
D. Either (A) or (B)
Answer» D. Either (A) or (B)
Discussion
5.

Which of the following insulating materials was suitable for low temperature applications ?
A. Asbestos paper
B. Diatomaceous earth
C. 80 percent magnesia
D. Cork
Answer» C. 80 percent magnesia
Discussion
6.

It is desirable to operate the arc furnaces at power factor of_____________?
A. zero
B. 0.707 lagging
C. unity
D. 0.707 leading
Answer» C. unity
Discussion
7.

By the use of which of the following, high frequency power supply for induction furnaces can be obtained ?
A. Coreless transformers
B. Current transformers
C. Motor-generator set
D. Multi-phase transformer
Answer» D. Multi-phase transformer
Discussion
8.

The temperature inside a furnace is usually measured by which of the following ?
A. Optical pyrometer
B. Mercury thermometer
C. Alcohol thermometer
D. Any of the above
Answer» B. Mercury thermometer
Discussion
9.

In an electric room heat convector the method of heating used is______________?
A. arc heating
B. resistance heating
C. induction heating
D. dielectric heating
Answer» C. induction heating
Discussion
10.

For heating element high resistivity material is chosen to______________?
A. reduce the length of heating element
B. increase the life of the heating element
C. reduce the effect of oxidation
D. produce large amount of heat
Answer» B. increase the life of the heating element
Discussion
11.

Which of the following devices is necessarily required for automatic temperature control in a furnace ?
A. Thermostat
B. Thermocouple
C. Auto-transformer
D. Heating elements of variable resis-tance material
Answer» C. Auto-transformer
Discussion
12.

Induction furnaces are employed for which of the following ?
A. Heat treatment of castings
B. Heating of insulators
C. Melting aluminium
D. None of the above
Answer» B. Heating of insulators
Discussion
13.

Which of the following will happen if the thickness of refractory wall of furnace is increased ?
A. Heat loss through furnace wall will increase
B. Temperature inside the furnace will fall
C. Temperature on the outer surface of furnace walls will drop
D. Energy consumption will increase
Answer» D. Energy consumption will increase
Discussion
14.

A non-dimensional number generally associated with natural convection heat transfer is____________?
A. Prandtl number
B. Grashoff number
C. Pecelet number
D. Nusselt number
Answer» C. Pecelet number
Discussion
15.

Induction heating process is based on which of the following principles ?
A. Thermal ion release principle
B. Nucleate heating principle
C. Resistance heating principle
D. Electro-magnetic induction princi¬ple
Answer» E.
Discussion
16.

The process of heat transfer during the reentry of satellites and missiles, at very high speeds, into earth’s atmosphere is known as_______________?
A. ablation
B. radiation
C. viscous dissipation
D. irradiation
Answer» B. radiation
Discussion
17.

Radiant heating is used for which of the following ?
A. Annealing of metals
B. Melting of ferrous metals
C. Heating of liquids in electric kettle
D. Drying of paints and varnishes
Answer» E.
Discussion
18.

Direct arc furnaces have which of the following power factors ?
A. Unity
B. Low, lagging
C. Low, leading
D. Any of the above
Answer» C. Low, leading
Discussion
19.

In direct arc furnace, which of the following has high value ?
A. Current
B. Voltage
C. Power factor
D. All of the above
Answer» B. Voltage
Discussion
20.

Which of the following is an advantage of eddy current heating ?
A. The amount of heat generated can be controlled accurately
B. Heat at very high rate can be gene-rated
C. The area of the surface over which heat is produced can be accurately controlled
D. All of the above
Answer» E.
Discussion
21.

For radiant heating around 2250°C, the heating elements are made of____________?
A. copper alloy
B. carbon
C. tungsten alloy
D. stainless steel alloy
Answer» D. stainless steel alloy
Discussion
22.

The electrode of a direct arc furnace is made of____________?
A. tungsten
B. graphite
C. silver
D. copper
Answer» C. silver
Discussion
23.

Due to which of the following reasons it is desirable to have short arc length ?
A. To achieve better heating
B. To increase the life of roof refractory
C. To have better stirring action
D. To reduce problem of oxidation
E. All of the above
Answer» F.
Discussion
24.

In a domestic cake baking oven the temperature is controlled by________________?
A. voltage variation
B. thermostat
C. auto-transformer
D. series-parallel operation
Answer» E.
Discussion
25.

Radiations from a black body are proportional to____________?
A. T1
B. T2
C. T3
D. T*
Answer» E.
Discussion
26.

In an electric press mica is used_____________?
A. as an insulator
B. as a device for power factor improvement
C. for dielectric heating
D. for induction heating
Answer» B. as a device for power factor improvement
Discussion
27.

In arc furnace the function of choke is______________?
A. to stabilize the arc
B. to imprpve, power factor
C. to reduce severity of the surge
D. none of the above
Answer» B. to imprpve, power factor
Discussion
28.

Ajax Wyatt furnace is started when____________?
A. it is filled below core level
B. it is filled above core level
C. it is fully empty
D. none of the above
Answer» C. it is fully empty
Discussion
29.

In heating the ferromagnetic material by induction heating, heat is produced due to_____________?
A. induced current flow through the charge
B. hysteresis loss taking place below curie temperature
C. due to hysteresis loss as well as eddy current loss takingplace in the charge
D. none of the above factors
Answer» D. none of the above factors
Discussion
30.

Which of the following methods is used to control temperature in resistance furnaces ?
A. Variation of resistance
B. Variation of voltage
C. Periodical switching on and off of the supply
D. All of the above methods
Answer» E.
Discussion
31.

Hysteresis loss and eddy current loss are used in____________?
A. induction heating of steel
B. dielectric heating
C. induction heating of brass
D. resistance heating
Answer» B. dielectric heating
Discussion
32.

In electric press, mica is used because it is _________ conductor of heat but/and __________ conductor of electricity?
A. bad, good
B. bad, bad
C. good, bad
D. good, good
Answer» D. good, good
Discussion
33.

Resistance variation method of temperature control is done by connecting resistance elements in_____________?
A. series
B. parallel
C. series-parallel connections
D. star-delta connections
E. all of the above ways
Answer» F.
Discussion
34.

In resistance heating highest working temperature is obtained from heating elements made of_____________?
A. nickel copper
B. nichrome
C. silicon carbide
D. silver
Answer» D. silver
Discussion
35.

For intermittent work which of the following furnaces is suitable ?
A. Indirect arc furnace
B. Core less furnace
C. Either of the above
D. None of the above
Answer» D. None of the above
Discussion
36.

In the indirect resistance heating method, maximum heat-transfer takes place by____________?
A. radiation
B. convection
C. conduction
D. any of the above
Answer» B. convection
Discussion
37.

By which of the following methods the temperature inside arc nace can be varied ?
A. By disconnecting some of the heating elements
B. By varying the operating voltage
C. By varying the current through heating elements
D. By any of the above method
Answer» E.
Discussion
38.

In a resistance furnace the atmosphere is_____________?
A. oxidizing
B. deoxidising
C. reducing
D. neutral
Answer» B. deoxidising
Discussion
39.

Which of the following has the highest value of thermal conductivity ?
A. Water
B. Steam
C. Sold ice
D. Melting ice
Answer» D. Melting ice
Discussion
40.

In induction heating ___________ is abnormally high?
A. phase angle
B. frequency
C. current
D. voltage
Answer» C. current
Discussion
41.

Heat transfer by condition will not occur when____________?
A. bodies are kept in vacuum
B. bodies are immersed in water
C. bodies are exposed to thermal radiations
D. temperatures of the two bodies are identical
Answer» E.
Discussion
42.

A perfect black body is one that_____________?
A. transmits all incident radiations
B. absorbs all incident radiations
C. reflects all incident radiations
D. absorbs, reflects and transmits all incident radiations
Answer» C. reflects all incident radiations
Discussion
43.

For the transmission of heat from one body to another__________?
A. temperature of the two bodies must be different
B. both bodies must be solids
C. both bodies must be in contact
D. at least one of the bodies must have some source of heating
Answer» B. both bodies must be solids
Discussion
44.

Heat is transferred simultaneously by condition, convection and radiation_____________?
A. inside boiler furnaces
B. during melting of ice
C. through the surface of the insulted pipe carrying steam
D. from refrigerator coils to freezer of a refrigerator
Answer» B. during melting of ice
Discussion
45.

Which of the following is an advantage of heating by electricity ?
A. Quicker operation
B. Higher efficiency
C. Absence of flue gases
D. All of the above
Answer» E.
Discussion
46.

Which of the following heating methods has maximum power factor ?
A. Arc heating
B. Dielectric heating
C. Induction heating
D. Resistance heating
Answer» E.
Discussion
47.

_________ has the highest value of thermal conductivity?
A. Copper
B. Aluminium
C. Brass
D. Steel
Answer» B. Aluminium
Discussion
48.

is used for heating non-conducting materials?
A. Eddy current heating
B. Arc heating
C. Induction heating
D. Dielectric heating
Answer» E.
Discussion
49.

Which of the following methods of heating is not dependent on the frequency of supply ?
A. Induction heating
B. Dielectric heating
C. Electric resistance heating
D. All of the above
Answer» D. All of the above
Discussion
50.

method has leading power factor____________?
A. Resistance heating
B. Dielectric heating
C. Arc heating
D. Induction heating
Answer» C. Arc heating
Discussion