The quantity of heat required to melt a given volume of metal does not depend on______

The heat to transform the metal from solid to liquid phase at the melting point

Composition of elements in the melt

The heat to transform the metal from solid to liquid phase at the melting point

The heat to raise the temperature of the solid metal to its melting point

15 + Mcqs in Solidification of Fusion Welds Page 1 McqOptions

1.	Arc shielding is accomplished by covering the electrode tip, arc, and molten weld pool with a blanket of gas or flux, or both, which inhibit exposure of the weld metal to air.
A.	True
B.	False
Answer» B. False

Discussion

2.	A flux is a substance used to prevent the formation of oxides and other unwanted contaminants, or to dissolve them and facilitate removal.
A.	False
B.	True
Answer» C.

Discussion

3.	The quantity of heat required to melt a given volume of metal does not depend on______
A.	The melting point of the metal
B.	Composition of elements in the melt
C.	The heat to transform the metal from solid to liquid phase at the melting point
D.	The heat to raise the temperature of the solid metal to its melting point
Answer» C. The heat to transform the metal from solid to liquid phase at the melting point

Discussion

4.	The power source in a particular welding setup generates 4000 W that can be transferred to the work surface with a heat transfer factor = 0.9. The metal to be welded is low carbon steel, whose melting temperature, is 1800 K. The melting factor in the operation is 0.6. A continuous fillet weld is to be made with a cross-sectional area = 20 mm². Determine the travel speed at which the welding operation can be accomplished? (K = 3.33 *10^-6)
A.	59.5mm/sec
B.	10.49mm/se
C.	3.65mm/sec
D.	4.56mm/sec
Answer» C. 3.65mm/sec

Discussion

5.	A gas tungsten arc-welding operation is performed at a current of 500 A and voltage of 20 V. The melting factor f2 = 0.5, and the unit melting energy for the metal Um = 10 Jmm^-3. Calculate the volume of metal welded? (Heat transfer factor is 0.7)
A.	350mm/sec
B.	950mm/sec
C.	450mm/sec
D.	550mm/sec
Answer» B. 950mm/sec

Discussion

6.	If the total power generated is given as 3000W. Calculate the rate of heat generation at the weld if the melting factor is given as 0.6 and the heat transfer factor as 0.8?
A.	1444J/s
B.	1434J/s
C.	1240J/s
D.	1440J/s
Answer» E.

Discussion

7.	A gas tungsten arc-welding operation is performed at a current of 300 A and voltage of 20V. Calculate the total power in the operation?
A.	6000W
B.	150W
C.	600W
D.	1500W
Answer» B. 150W

Discussion

8.	In the case of arc welding find the arc time, if the time for which the arc is switched on is given as 3hrs and the hours worked with that is given as 1hr?
A.	3hrs
B.	1.5hrs
C.	6hrs
D.	9hrs
Answer» B. 1.5hrs

Discussion

9.	Calculate the net heat available for welding if the heat transfer factor f1, melting factor f2 and the total heat supplied are given as 0.8, 0.9, 1000J respectively?
A.	720J
B.	100J
C.	1000J
D.	110J
Answer» B. 100J

Discussion

10.	Typical fusion-weld joint in which filler metal has been added consists of several zones.
A.	True
B.	False
Answer» B. False

Discussion

11.	The heat to transform the metal from solid to liquid phase at the melting point, which depends on the metal s heat of fusion. Calculate the unit energy for melting if the melting temperature is 1000K? (K = 3.33 * 10^-6).
A.	3.33
B.	6.66
C.	9.99
D.	3.33*10<sup>-3</sup>
Answer» B. 6.66

Discussion

12.	In which joint type, the parts lie in the same plane and are joined at their edges?
A.	Butt
B.	Corner
C.	Lap
D.	Tee
Answer» B. Corner

Discussion

13.	Which among the following is not a fusion welding technique?
A.	Arc welding
B.	Oxy-fuel welding
C.	Resistance welding
D.	Diffusion welding
Answer» E.

Discussion

14.	A fusion-welding operation in which no filler metal is added is referred to as a/an _____
A.	Compile weld
B.	Autogenous weld
C.	Filler Weld
D.	Damper weld
Answer» C. Filler Weld

Discussion

15.	Which among the following is a property of fusion welding not of solid state welding?
A.	Filler metal is added
B.	Heat is applied
C.	Used to join metals
D.	Nothing can differentiate them
Answer» B. Heat is applied

Discussion

Explore topic-wise MCQs in Phase Transformation.

Arc shielding is accomplished by covering the electrode tip, arc, and molten weld pool with a blanket of gas or flux, or both, which inhibit exposure of the weld metal to air.

A flux is a substance used to prevent the formation of oxides and other unwanted contaminants, or to dissolve them and facilitate removal.

The quantity of heat required to melt a given volume of metal does not depend on______

A gas tungsten arc-welding operation is performed at a current of 500 A and voltage of 20 V. The melting factor f2 = 0.5, and the unit melting energy for the metal Um = 10 Jmm-3. Calculate the volume of metal welded? (Heat transfer factor is 0.7)

If the total power generated is given as 3000W. Calculate the rate of heat generation at the weld if the melting factor is given as 0.6 and the heat transfer factor as 0.8?

A gas tungsten arc-welding operation is performed at a current of 300 A and voltage of 20V. Calculate the total power in the operation?

In the case of arc welding find the arc time, if the time for which the arc is switched on is given as 3hrs and the hours worked with that is given as 1hr?

Calculate the net heat available for welding if the heat transfer factor f1, melting factor f2 and the total heat supplied are given as 0.8, 0.9, 1000J respectively?

Typical fusion-weld joint in which filler metal has been added consists of several zones.

The heat to transform the metal from solid to liquid phase at the melting point, which depends on the metal s heat of fusion. Calculate the unit energy for melting if the melting temperature is 1000K? (K = 3.33 * 10-6).

In which joint type, the parts lie in the same plane and are joined at their edges?

Which among the following is not a fusion welding technique?

A fusion-welding operation in which no filler metal is added is referred to as a/an _____

Which among the following is a property of fusion welding not of solid state welding?

A gas tungsten arc-welding operation is performed at a current of 500 A and voltage of 20 V. The melting factor f2 = 0.5, and the unit melting energy for the metal Um = 10 Jmm^-3. Calculate the volume of metal welded? (Heat transfer factor is 0.7)

The heat to transform the metal from solid to liquid phase at the melting point, which depends on the metal s heat of fusion. Calculate the unit energy for melting if the melting temperature is 1000K? (K = 3.33 * 10^-6).