Power Systems
The commercial sources of energy are

 solar, wind, biomass.
  fossile fuels and radioactive substances.
 none of above.
 wood, animal wastes and agricultural wastes.

ANSWER DOWNLOAD EXAMIANS APP

Power Systems
The power level of nuclear reactor can be increase by ( K = multiplication factor )

  raising the value of K above 1, but later bringing it back to K = 1.
 lowering the value of K below 1 but later bringing it back to K = 1.
 raising the value of K above 1 and keeping it at raised value.
 lowering the value of K below and keeping at that lowered value.

ANSWER DOWNLOAD EXAMIANS APP