51. Absorptivity of a perfect black body is
- Zero
- 0-1
- 1
- Cannot be determined
52. Microwave ovens operate at a frequency of
- 2.45 GHz
- 1.37 GHz
- 5.52 GHz
- 3.37 GHz
53. A freshly painted layer may be dried electronically by
- Convective heating
- Induction heating
- Dielectric heating
- Emissive heating