Induction heating - Electrical Engineering (MCQ) questions and answers

1)   The dielectric strength of air gap is

a. 2.11kV/cm
b. 21.1kV/m
c. 21.1kV/cm
d. 2.11kV/m
Answer  Explanation 

ANSWER: 21.1kV/cm

Explanation:
No explanation is available for this question!


2)   When the air gap is smaller in induction motor then its

a. magnetizing current reduces
b. starting torque increases
c. both a and b
d. neither a nor b
Answer  Explanation 

ANSWER: magnetizing current reduces

Explanation:
No explanation is available for this question!


3)   The temperature produced in indirect arc furnace is

a. More than in direct arc furnace
b. Less than direct arc furnace
c. Equal to direct arc furnace
d. None of these
Answer  Explanation 

ANSWER: Less than direct arc furnace

Explanation:
No explanation is available for this question!


4)   Which type of heating is used for sterilization?

a. High frequency eddy current heating
b. Coreless type heating
c. Core type heating
d. Dielectric heating
Answer  Explanation 

ANSWER: Dielectric heating

Explanation:
No explanation is available for this question!


5)   The rate of heat produced by dielectric heating is increased by

a. Increasing frequency and voltage supply
b. Increasing frequency and decreasing voltage supply
c. Decreasing frequency and voltage supply
d. Decreasing frequency and increasing voltage supply
Answer  Explanation 

ANSWER: Increasing frequency and voltage supply

Explanation:
No explanation is available for this question!


6)   High frequency eddy current heating is used for

a. Melting of non-ferrous metals
b. High grade alloy steel production
c. Hardening the surfaces of materials being heated
d. Vacuum heating
Answer  Explanation 

ANSWER: Hardening the surfaces of materials being heated

Explanation:
No explanation is available for this question!


7)   For improving the power factor of coreless type induction furnace,

a. Capacitor is used
b. Inductor is used
c. Resistor is used
d. Transistor is used
Answer  Explanation 

ANSWER: Capacitor is used

Explanation:
No explanation is available for this question!


8)   In indirect core type of furnace, the element is heated by induction, which transfer the heat to the charge by

a. Conduction
b. Radiation
c. Convection
d. All of these
Answer  Explanation 

ANSWER: Radiation

Explanation:
No explanation is available for this question!


9)   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
Answer  Explanation 

ANSWER: High and power factor is low

Explanation:
No explanation is available for this question!


10)   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
Answer  Explanation 

ANSWER: Low frequency, high frequency

Explanation:
No explanation is available for this question!


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