Deck 4: Welding and Induction Motor Starting Methods

Question 1

and the rotor current I2 are zero at_______________    

A)ns
B)2ns
C)zero
D)slip of 50%

Answer 1

ns

Question 2

If use auto transformer method starting to start an induction motor to replace star-delta method, then the required tapping on the transformer will be_______________    

A)57.73%
B)86.7%
C)57%
D)66.66%

Answer 2

57.73%

Question 3

The starting method for a 3-phase squirrel-cage induction motor which is inferior in view of poor starting torque per ampere of line current drawn is?

A)series-inductor method of starting
B)direct-on-line starting
C)auto-transformer method
D)star-delta method

Answer 3

series-inductor method of starting

Question 4

volts, I = 200 A, and the cross-sectional area of the weld bead is 30 mm2. Estimate the welding speed if the workpiece and electrode are made of (a) aluminum, (b) carbon steel, and (c) titanium. Use an efficiency of 75%.

A)35 mm/s
B)34.5 mm/s
C)36 mm/s
D)46 mm/s

Question 5

Upon which of the following parameters does the current intensity in arc welding depend?

A)stability of arc
B)electrode diameter
C)gap between the electrode and parent metals
D)thickness of parent metals

Question 6

In which of the following welding processes we use two non-consumable electrodes?

A)mig
B)tig
C)atomic hydrogen
D)submerged arc

Question 7

Which of the following brazing process is good for mass scale joining?

A)furnace
B)induction
C)dip
D)torch

Question 8

For grey cast iron, which of the following welding methods is preferable?

A)mig
B)submerged arc
C)gas flame
D)electric arc

Question 9

Due to which of the following reasons, flux is not used in atomic hydrogen welding?

A)the burning hydrogen shields the molten metal
B)two electrodes are coated which gradually release the flux
C)the filler rod is coated with flux
D)one of the two electrodes is coated which releases the flux

Question 10

In resistance welding, between the electrodes, the nature of current and voltage parameters being used?

A)high current, high voltage
B)low current, high voltage
C)low current, low voltage
D)high current, low voltage

Question 11

Which of the following welding process in which heat is produced for welding by a chemical reaction?

A)resisting welding
B)thermit welding
C)forge welding
D)gas welding

Question 12

The maximum diameter of electrodes being used in submerged arc welding?

A)30 mm
B)20 mm
C)15 mm
D)10 mm

Question 13

Which of the following gases are used in Tungsten inert gas welding?

A)helium and neon
B)hydrogen and oxygen
C)argon and helium
D)carbon dioxide and hydrogen

Question 14

Which of the following materials necessitates preheating in welding?

A)copper
B)aluminium
C)cast iron
D)stainless steel

Question 15

Which of the following is also called "gas welding"?

A)oxy fuel gas welding
B)metallic welding
C)arc welding
D)fuel gas welding

Question 16

How many types of flames are there in welding?

A)1
B)2
C)3
D)4

Question 17

In which of the following type of flame, oxygen is in excess proportion with acetylene?

A)neutral flame
B)oxidizing flame
C)carburizing flame
D)both oxidizing flame and carburizing flame

Question 18

In which of the following type of flame, oxygen is deficient in proportion with acetylene?

A)neutral flame
B)oxidizing flame
C)carburizing flame
D)both oxidizing flame and carburizing flame

Question 19

For brazing, soldering and flame hardening which of the following flame is used?

A)neutral flame
B)oxidizing flame
C)carburizing flame
D)both oxidizing flame and carburizing flame

Question 20

The inner cone of the flame in welding has the following nature?

A)highest temperature
B)coldest temperature
C)moderate temperature
D)uncertain

Question 21

The oxy acetylene gas welding is a type of?

A)endothermic reaction
B)exothermic reaction
C)neutral reaction
D)both endothermic reaction and exothermic reaction

Question 22

The chemical formula of acetylene is?

A)c?h?
B)c?h?.
C)c?h?oh
D)c?h?

Question 23

Amount of time during which the transformer will be used for welding under normal loading condition is known as?

A)hold time
B)off time
C)weld time
D)duty cycle

Question 24

Amount of voltage required to generate the arc under no load condition is called?

A)open circuit voltage
B)closed circuit voltage
C)short circuit voltage
D)arc voltage

Question 25

In which of the following gas welding process a non-consumable electrode is used?

A)submerged arc welding
B)tungsten inert gas welding
C)stud welding
D)gas metal arc welding