Heating and Welding

A. Thermostat
B. Thermocouple
C. Auto-transformer
D. Heating elements of variable resis-tance material

A. Unity
B. Low, lagging
C. Low, leading
D. Any of the above

A. The amount of heat generated can be controlled accurately
B. Heat at very high rate can be gene-rated
C. The area of the surface over which heat is produced can be accurately controlled
D. All of the above

A. Annealing of metals
B. Melting of ferrous metals
C. Heating of liquids in electric kettle
D. Drying of paints and varnishes

A. copper alloy
B. carbon
C. tungsten alloy
D. stainless steel alloy

A. tungsten
B. graphite
C. silver
D. copper

A. Current
B. Voltage
C. Power factor
D. All of the above

A. voltage variation
B. thermostat
C. auto-transformer
D. series-parallel operation

A. To achieve better heating
B. To increase the life of roof refractory
C. To have better stirring action
D. To reduce problem of oxidation
E. All of the above

A. as an insulator
B. as a device for power factor improvement
C. for dielectric heating
D. for induction heating