Category: Heating and Welding

A. temperature of the two bodies must be different
B. both bodies must be solids
C. both bodies must be in contact
D. at least one of the bodies must have some source of heating

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

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. to stabilize the arc
B. to imprpve, power factor
C. to reduce severity of the surge
D. none of the above

A. oxidizing
B. deoxidising
C. reducing
D. neutral

A. Water
B. Steam
C. Sold ice
D. Melting ice

A. Induction heating
B. Dielectric heating
C. Electric resistance heating
D. All of the above

A. Variation of resistance
B. Variation of voltage
C. Periodical switching on and off of the supply
D. All of the above methods

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

A. By disconnecting some of the heating elements
B. By varying the operating voltage
C. By varying the current through heating elements
D. By any of the above method