Question

C4. Multiple Choice Questions (MCQs): Choose the correct answer for each of the following.
1. A good fuel should have
(a) low ignition temperature,
(b) high calorific value.
(c) low cost and easy availability.
(d) all of them.
2. Which of the following fuel has highest calorific value?
(a) Wood
(b) Coal
(c) Hydrogen
(d) Petrol
3. Water is used to extinguish fire because it
(a) reduces the ignition temperature of the burning substance.
(b) cools the burning substance below its ignition temperature.
(c) makes a blanket of water vapour and cuts off the oxygen.
(d) both (b) and (c).
4. In carbon dioxide based fire extinguishers, carbon dioxide is present in
(a) liquéfied and compressed form.
(b) powdered sodium bicarbonate form.
(c) powdered potassium bicarbonate form. (d) all of them.
5. When a wax candle burns, which part of it catches fire?
(a) Wick
(b) Wax vapour
(c) Liquid wax (d) Solid wax​

Answer 1

Answer:

1 d) all of them

2 c) Hydrogen

3 d ) both b and c

4 d ) all of them

5 a) Wick

Answer 2

Answer:

1)=all of them

2). hydrogen

3). both (b) and (c)

4) all of them

5). wick