Q.1
By the use of which of the following, high frequency power supply for induction furnaces can be obtained?
Q.2
Which of the following methods is used to control temperature in resistance furnaces?
Q.3
It is desirable to operate the arc furnaces at power factor of
Q.4
A perfect black body is one that
Q.5
For heating element high resistivity material is chosen to
Q.6
The temperature inside a furnace is usually measured by which of the following?
Q.7
In an electric room heat convector the method of heating used is Resistance heating
Q.8
Which of the following heating methods has maximum power factor?
Q.9
What is the code word to notify workers that the machine is about to be on
  • i'm WORKING HERE
  • POWER
  • CLEAR
Q.10
Which of the following is not an important factor when heat treating
  • the rate the metal is cooled
  • the tempurature
  • the method used to heat the metal
  • material around the metal
Q.11
Which of the following is NOT true about a steel that is quenched and tempered
  • has good strength
  • Has good hardness
  • It is brittle
Q.12
Which result from an oxyacetylene torch test indicates that a metal is not suitable for welding
  • the metal gives off a lot of sparks
  • the weld pool is fluid and has good tension
  • non of the above
Q.13
Which of the following statements is NOT true of nonferrous metals
  • They have distinctive colors
  • They are Magnetic
  • they do not spark
  • They are soft
Q.14
In direct arc furnace, which of the following has high value?
  • Current
  • Voltage
  • Power factor
  • All of the above
Q.15
For intermittent work which of the following furnaces is suitable?
  • Indirect arc furnace
  • Core less furnace
  • Either of the above
  • None of the above
Q.16
Due to which of the following reasons it is desirable to have short arc length?
  • To achieve better heating
  • To increase the life of roof refractory
  • To have better stirring action
  • All of the above
Q.17
In a domestic cake baking oven the temperature is controlled by
  • Voltage variation
  • Thermostat
  • Autotransformer
  • Series-parallel operation
Q.18
Which of the following is an advantage of heating by electricity?
  • Quicker operation
  • Higher efficiency
  • Absence of flue gases
  • All of the above
Q.19
In heating the ferromagnetic material by induction heating, heat is produced due to
  • Induced current flow through the charge
  • Hysteresis loss taking place below Curie temperature
  • Due to hysteresis loss as well as eddy current loss taking place in the charge
  • None of the above factors
Q.20
Resistance variation method of temperature control is done by connecting resistance elements in
  • Series
  • Parallel
  • Series-parallel connections
  • All of the above ways
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