A. Variation of resistance
B. Variation of voltage
C. Periodical switching on and off of the supply
D. All of the above methods
A. to stabilize the arc
B. to imprpve, power factor
C. to reduce severity of the surge
D. none of the above
A. induction heating of steel
B. dielectric heating
C. induction heating of brass
D. resistance heating
A. bad, good
B. bad, bad
C. good, bad
D. good, good
A. induced current flow through the charge
B. hysteresis loss taking place below curie temperature
C. due to hysteresis loss as well as eddy current loss takingplace in the charge
D. none of the above factors
A. series
B. parallel
C. series-parallel connections
D. star-delta connections
E. all of the above ways
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