Journal of Astrophysics and Astronomy

, Volume 6, Issue 2, pp 85–100 | Cite as

Energetics of the Kerr-Newman black hole by the penrose process

  • Manjiri Bhat
  • Sanjeev Dhurandhar
  • Naresh Dadhich


We have studied in detail the energetics of Kerr-Newman black hole by the Penrose process using charged particles. It turns out that the presence of electromagnetic field offers very favourable conditions for energy extraction by allowing for a region with enlarged negative energy states much beyondr = 2M, and higher negative values for energy. However, when uncharged particles are involved, the efficiency of the process (defined as the gain in energy/input energy) gets reduced by the presence of charge on the black hole in comparison with the maximum efficiency limit of 20.7 per cent for the Kerr black hole. This fact is overwhelmingly compensated when charged particles are involved as there exists virtually no upper bound on the efficiency. A specific example of over 100 per cent efficiency is given.

Key words

black hole energetics Kerr-Newman black hole Penrose process energy extraction 


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Copyright information

© Indian Academy of Sciences 1985

Authors and Affiliations

  • Manjiri Bhat
    • 1
  • Sanjeev Dhurandhar
    • 1
  • Naresh Dadhich
    • 1
  1. 1.Department of MathematicsUniversity of PoonaPune

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