Heat in water and air is transferred by
A. Conduction
B. Convection
C. Radiation
D. Either conduction or convection
The efficiency of heating is more for
A. Solid fuels
B. Oil heating
C. Gas heating
D. Electric heating
The heat can be transferred from high temperature body to low temperature body by
A. Conduction method
B. Convection method
C. Radiation method
D. All of these
In induction heating, the heat produced is
A. Directly proportional to the induced voltage and inversely proportional to the resistance
B. Inversely proportional to the induced voltage and directly proportional to the resistance
C. Directly proportional to the square of induced voltage and inversely proportional to the resistance
D. Inversely proportional to the square of induced voltage and directly proportional to the resistance
The core type induction furnace and the coreless type induction furnace are
A. Low frequency, high frequency
B. Low frequency, low frequency
C. High frequency, high frequency
D. High frequency, low frequency
In direct core type induction furnaces, the leakage reactance of the magnetic circuit is
A. High and power factor is also high
B. Low and power factor is high
C. High and power factor is low
D. Low and power factor is also low