Page 2 - HA OBJ

Subjective Questions;-

Q. No. Questions Skill Marks

1. Give one word for the temperature at which a substance burns. U 1

2. Name the chemical substance which is replaced in making a U 1
matchstick these days.

3. Choose the correct option from the following: U 1
(a) If both Assertion and Reason are correct and Reason is the
correct explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not
the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If Assertion is incorrect but Reason is correct.
(e) If Assertion & Reason both are incorrect.
Assertion (A): Fire can be extinguished by cutting off the
supply of air.

Reason (R): Cutting the supply of air increases the
temperature.

4. a. Define ignition temperature. R + 1 + 2
b. Why an empty paper cup burns whereas a paper cup U = 3
containing water does not when shown over the flame?

5. a. What are the conditions necessary for combustion? U + 3 + 2
b. Why we should not throw water on fire caused due to A = 5
electrical short circuit. How can these types of fire be
extinguished?

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