An electric bulb rated as $200\, {W}$ at $100 \,{V}$ is used in a circuit having $200\, {V}$ supply. The resistance $'R'$ that must be put in series with the bulb so that the bulb delivers the same power is $.....\,\Omega$
  • A$15$
  • B$20$
  • C$5$
  • D$50$
JEE MAIN 2021, Medium
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