070/21

94. Which is not true about calcium carbide ?
A) It is brittle
B) It absorbs moisture from atmosphere
C) It produces acetylene when brought in contact with water
D) It is soluble in kerosene oil

95. Ina gas cut plate, the cut shows grooves and has deep drag lines. This is due to
A) Tip too close to the cut surface
B) Too much travel speed
C) Less oxygen pressure
D) Smaller size cutting nozzle

96. What percentage of chromium and nickel are usually present in stainless steel ?
A) 15% Chromium, 5% Nickel B) 16% Chromium, 6% Nickel
C) 17% Chromium, 7% Nickel D) 18% Chromium, 8% Nickel

97. Which type of welding source is preferred for welding of non-ferrous metals ?
A) Welding transformer B) Welding rectifier
C) Motor-generator set D) Capacitor set

98. In resistance welding, if the current is doubled, the heating effect becomes
A) Double B) Four times C) Eight times D) Sixteen times

99. The presence of oxygen can reduce
A) Strength B) Ductility C) Malleability D) Toughness

100. Which of the following elements is added to steel to increase its resistance to corrosion
in environments like seawater ?

A) Aluminium B) Copper C) Titanium D) Vanadium