By the use of which of the following, high frequency power supply for induction furnaces can be obtained ?

A. zero
B. 0.707 lagging
C. unity
D. 0.707 leading

A. inside boiler furnaces
B. during melting of ice
C. through the surface of the insulted pipe carrying steam
D. from refrigerator coils to freezer of a refrigerator

A. lower melting point
B. higher temperature coefficient
C. high specific resistance
D. all of the above

A. To avoid initial rush of current
B. To avoid change in kW rating with temperature
C. Both (A) and (B)
D. Either (A) or (B)

A. induction heating of steel
B. dielectric heating
C. induction heating of brass
D. resistance heating

A. series
B. parallel
C. series-parallel connections
D. star-delta connections
E. all of the above ways