High Voltage Engineering.

properties of dielectric at dc ✘ dispersion in insulation ✘ high frequency high voltages ✘ modulation ratio frequencies. ✔

power frequency tests ✘ impulse tests ✘ both (A) and (B) above ✘ none of the above. ✔

bushings to withstand vibrations ✘ insulation to withstand transient voltages ✘ windings to withstand voltage fluctuations ✘ all of the above. ✔

corona discharges in air ✘ internal or partial discharges in insulation ✘ sparking ✘ any of the above. ✔

1.5 times ✘ 2.5 times ✘ 4.0 times ✘ 5.0 times ✔

nature of applied voltage ✘ imperfections in dielectric material ✘ pressure, temperature and humidity ✘ all of the above. ✔

Nitrogen ✘ Carbon dioxide ✘ Sulphur hexafluoride ✘ Freon. ✔

Particle accelerators ✘ EHT of color TV ✘ Field emission tubes ✘ X-rays. ✔

100 MV/cm ✘ 50 MV/cm ✘ 50 kV/cm ✘ 500 V/cm. ✔

magnetic bum ✘ vibrations ✘ mechanical stresses produced by the electrical field ✘ electrical stresses produced by the voltage fluctuations. ✔