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8th Class Science Combustion and Flame Question Bank Combustion and Flame Conceptive Objective Problems

  • question_answer
    Four substances P, Q, R, and S were brought one by one near a lighted candle. It was observed that only substance Q bums readily. Substances P and R burn after sustained heating and substance S does not bum at all. Among all the substances given, which substance has the lowest ignition temperature?

    A)  P                                           

    B)  Q

    C)  R                                           

    D)  S

    Correct Answer: B

    Solution :

      Ignition temperature is the minimum temperature at which a substance starts burning. Substance Q burns readily. Hence, it has the minimum ignition temperature. P and R burn, but only after sustained heating. Therefore, their ignition temperature is higher than that of Q. S does not burn at all. Therefore, it has the maximum ignition temperature. The correct answer is B.


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