Advertisements
Advertisements
प्रश्न
Anu wants to boil water quickly in a test tube. On observing the different zones of the flame, she is not able to decide which zone of the flame will be best for boiling water quickly. Help her in this activity.
उत्तर
Anu should keep her test tube in the outermost zone or non-luminous zone of the flame because it is the hottest zone of a flame and has more temperature.
In the outer zone of a flame, complete combustion of the fuel takes place because there is plenty of air around it so, water in a test tube will boil quickly in this zone.
APPEARS IN
संबंधित प्रश्न
Make a labelled diagram of a candle flame.
If 4.5kg of fuel is completely burnt and amount of heat produced stands measured at 1, 80,000 KJ what is the calorific value.
Picture based question
Arul and Aakash were doing an experiment in which water was to be heated in a beaker. Arul kept the beaker near the wick in the yellow part of candle flame. Aakash kept the beaker in the outer most part to the flame. Whose water will get heated in a shorter time?
Magnesium ribbon on burning in air produces
The substances which gave very ______ ignition temperature and can easily catch fire with a flame are called ______ substances.
Match the following for the flame of a candle.
| Column A |
Column B (zone) |
Column C (colour) |
| (a) hottest part | (iii) outer zone of complete combustion | (x) blue |
| (b) moderately hot | (ii) middle zone of partial combustion | (z) yellow |
| (c) least hot | (i) innermost zone of complete combustion | (y) black |
If you hold a piece of iron wire with a pair of tongs inside a candle flame or a Bunsen burner flame, what will you observe? Will it produce a flame?
Write True/False against the following statement and also correct the false statement.
The substances which vaporise during burning, give flame.
You are provided with three watch glasses containing milk, petrol and mustard oil respectively. Suppose you bring a burning candle near these materials one by one, which material(s) will catch fire instantly and why?
Write a note on flame.
