1. In electrical resistance welding, material of electrode should have
a)higher electrical conductivities
b) higher thermal conductivities
c) sufficient strength to sustain high pressure at elevated temperatures
d) all of the above
Ans: d
2. Induction heating takes place in
a)conducting and magnetic materials
b)insulating materials
c)conducting materials which may be either magnetic or non-magentic materials
d) conducting but non-magnetic materials
Ans: c
3.The main advantage of dielectric heating is that
a)heating occurs in the material itself
b)heating occurs due to high frequency
c)it can be used for drying the explosives
d)None of the above
Ans: a
4.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 resistance material
Ans: b
5.In induction heating
a) magnetic materials can be easily treated in comparison to non magnetic materials
b)heat is produced due to current induced in the charge by electromagnetic action
c)the resistance of charge must be low and voltage applied must be high in order to produce sufficient heat
d)all of above
Ans: d
6.Direct resistance heating is used in
a)resistance welding
b)electrode boiler
c)salt bath furnace
d)all of the above
Ans: d
7.In induction heating, the depth up to which current will penetrate is proportional to
a)Frequency
b)((Frequency)2
c)1/√(Frequency
d)1/Frequency
Ans: c
8.In arc furnace the function of choke is
a)to stabilize the arc
b)to improve, power factor
c)to reduce severity of the surge
d)none of the above
Ans: a
9.The method of heating used for non conducting materials is
a)radiant heating
b)dielectric heating
c)resistance heating
d)induction heating
Ans: b
10.Induction furnaces are used for
a)Melting of aluminum
b)Heating of insulator
c)Heat treatment of casting
d)All of above
Ans: c
11.In submerged arc furnace the power is controlled by
a)varying the voltage applied to the electrodes
b)Varying the spacing between the electrodes
c)Either A or B
d)Varying the arc length
Ans: c
12.Projection welding is employed in
a)Butt welds
b)End to end welds
c)Lap welds
d)Stamped welds
Ans: d
13.Which of the following is a type of arc welding?
a)TIG (Tungsten Inert gas) welding
b)Friction welding
c)Acetylene welding
d)Ultrasonic welding
Ans: a
14.Which of the following falls under the category of fusion or non-pressure welding?
a)Resistance welding
b)Metal arc welding
c)Ultrasonic welding
d)Explosive welding
Ans: b
15. The temperature inside a furnace is usually measured by
a)Mercury thermometer
b)Optical thermometer
c)Alcohol thermometer
d)All of these
Ans: b
16.In electric resistance welding
a)The current required exceed 100A
b)The voltage required ranges from 4 to 12 V
c)The amount of power supplied to the weld usually ranges from 60 watts to 80 watts for each square mm of area.
d)All of these
Ans: d
17.In the spot welding
a)It is desirable to clean the sheets thoroughly before welding
b)The work pieces being welded are pressed together by mechanical pressure exert through electrodes
c)the current required is above 5000A and the voltage between the electrode is usually less than 2V (open circuit voltage is less than 12V)
d)All of these
Ans: d
18.Which of the following generators are used in arc welding
a)Shunt generators
b)Series Generator
c)Cumulative compound generators
d)Differential compound generators
Ans: d
19.In “argon arc welding” the electrode is made of
a)Carbon
b)Steel
c)Tungsten
d)No electrode is needed
Ans: c
20.Which one of the following is not a fusion welding process?
a) Gas Welding
b) Arc Welding
c) Brazing
d)Resistance Welding
Ans: c
21.Which of the following is different from the remaining?
a)Spot welding
b)Seam welding
c)Butt welding
d)Argon arc welding
Ans: d
22.A rectifier for welding has voltage/current characteristic as
a)Drooping
b)Rising
c)Static
d)Variable
Ans: a
23.The danger of electric shock is maximum
a)During arcing
b)After arcing
c)Before welding
d)While inserting an electrode into the holder
Ans: d
24.The eyes of the welding operator must be protected against
a)Ultraviolet radiation
b)Infrared radiations
c)Both (A) and (B)
d)Solar radiation
Ans: c
25.The welding transformer used in resistance welding will
a)Step up current
b)Step down current
c)Step up voltage
d)Step up power
Ans: a
26.A body at the temperature T K radiates heat in proportion to
a)T^2
b)1/T^2
c)T^4
d)1/T^4
Ans: c
27.If a body reflect entire radiation incident on it, then it is known as
a)Black body
b)Gray body
c)White Body
d)Transparent Body
Ans: c
28.Which of the following is of high value in case of induction heating?
a)Voltage
b)Current
c)Frequency
d)All of the above
Ans: c
29.The voltage applied to the electrodes for electroplating is in the range of:
a)1 6V DC
b)24V- 48V AC
c)1- 6V AC
d)24V- 48V DC
Ans: a
30.Gray iron usually welded by
a)Arc welding
b)Gas welding
c)TIG welding
d)MIC welding
Ans: b
“EXCELLENCE IS A CONTINUOUS PROCESS & NOT AN ACCIDENT”
BY- APJ Abdul Kalam
For a detail explanation of each question, you can watch this video…
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