Question 1 :
Candle is burning in the can. After sometimes, the candle is covered with glass. The flame of the candle:

Question 5 :
Why the innermost zone of candle flame is the least hot?<br/>

Question 6 :
Heat of combustion of$CH_{4},C_{2}H_{6},C_{2}H_{4}$ and$ C_{2}H_{2}$ gasses are - 212.8, -373.0, -337.0 and -310.5 Kcal respectively at the same temperature. The best fuel among these gases is :

Question 17 :
Match column 'A' with column 'B' as regard to characteristics of a flame and its zones.<table class="wysiwyg-table"><tbody><tr><td>'A'</td><td>'B'</td></tr><tr><td>a. Dark inner zone</td><td>1. Hottest part (No carbon)</td></tr><tr><td>b. Blue zone</td><td>2. Partial decomposition</td></tr><tr><td>c. Luminous zone</td><td>3. Unburnt vapours of wax</td></tr><tr><td>d. Non-luminous zone</td><td>4. Complete combustion</td></tr></tbody></table>