NextMockপরীক্ষা খুঁজুন, যেমন SSC CGL, UPPSC, Lekhpal
State PCS PYQPrelims 2022

BPSC – Combined Competitive Examination · প্রশ্ন 97

What change occurs in the weight of iron when it rusts?

  1. It first decreases and then increases
  2. It first increases and then decreases
  3. It remains the same
  4. It increases over a long time
  5. None of the above / More than one of the above
উত্তর দেখান ও ব্যাখ্যা

উত্তর: (D) It increases over a long time

ব্যাখ্যা

Rusting combines iron with oxygen and moisture, so the rusted object weighs more.

  • (A) ভুল

    Wrong: it does not first decrease.

  • (B) ভুল

    Wrong: it does not decrease (unless flakes fall off).

  • (C) ভুল

    Wrong: oxygen and water are added.

  • (D) সঠিক

    Correct: rust (Fe₂O₃·xH₂O) adds oxygen and water, increasing weight.

  • (E) ভুল

    Wrong: only one of the options A–D is correct.