The outermost part of the flame is the hottest one, so Rakesh’s water will get heated in a shorter time. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
The outermost part of the flame is the hottest one, so Rakesh’s water will get heated in a shorter time.
No, as rusting is a very slow process as compared to combustion and the heat evolve in combustion is much more than rusting. Rusting can take place at room temperature but combustion need an ignition temperature. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
No, as rusting is a very slow process as compared to combustion and the heat evolve in combustion is much more than rusting. Rusting can take place at room temperature but combustion need an ignition temperature.
Goldsmith uses the outermost zone of the flame for melting gold and silver because it is the hottest zone (complete combustion) of the flame. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
Goldsmith uses the outermost zone of the flame for melting gold and silver because it is the hottest zone (complete combustion) of the flame.
The ignition temperature of green leaves is higher than that of the dry leaves, so dry leaves catch fire easily. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
The ignition temperature of green leaves is higher than that of the dry leaves, so dry leaves catch fire easily.
CO2, being heavier than oxygen, covers the fire like a blanket. Since the contact between the fuel and oxygen is cut off, the fire is controlled. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
CO2, being heavier than oxygen, covers the fire like a blanket. Since the contact between the fuel and oxygen is cut off, the fire is controlled.
The calorific value of a fuel is expressed in a unit called kilojoule per kg (kJ/kg). https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
The calorific value of a fuel is expressed in a unit called kilojoule per kg (kJ/kg).
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not because the ignition temperature of paper is low as compare to the paper wrapped around an aluminium pipe. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not because the ignition temperature of paper is low as compare to the paper wrapped around an aluminium pipe.
LPG is a good fuel as compared to wood as it readily available and it is cheap. It burns easily in air at a moderate rate and it produces a large amount of heat. It does not leave behind any undesirable substances. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
LPG is a good fuel as compared to wood as it readily available and it is cheap. It burns easily in air at a moderate rate and it produces a large amount of heat. It does not leave behind any undesirable substances.
Water is not used to control fires involving electrical equipment because it may conduct electricity and harm those trying to douse the fire. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
Water is not used to control fires involving electrical equipment because it may conduct electricity and harm those trying to douse the fire.
CNG produces very small amounts of harmful products like Sulphur dioxide, oxides of nitrogen, oxides of sulphur etc. CNG is a cleaner fuel. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
CNG produces very small amounts of harmful products like Sulphur dioxide, oxides of nitrogen, oxides of sulphur etc. CNG is a cleaner fuel.
Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time?
The outermost part of the flame is the hottest one, so Rakesh’s water will get heated in a shorter time. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
The outermost part of the flame is the hottest one, so Rakesh’s water will get heated in a shorter time.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessCan the process of rusting be called combustion? Discuss.
No, as rusting is a very slow process as compared to combustion and the heat evolve in combustion is much more than rusting. Rusting can take place at room temperature but combustion need an ignition temperature. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
No, as rusting is a very slow process as compared to combustion and the heat evolve in combustion is much more than rusting. Rusting can take place at room temperature but combustion need an ignition temperature.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessWhich zone of a flame does a goldsmith use for melting gold and silver and why?
Goldsmith uses the outermost zone of the flame for melting gold and silver because it is the hottest zone (complete combustion) of the flame. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
Goldsmith uses the outermost zone of the flame for melting gold and silver because it is the hottest zone (complete combustion) of the flame.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessIt is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain.
The ignition temperature of green leaves is higher than that of the dry leaves, so dry leaves catch fire easily. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
The ignition temperature of green leaves is higher than that of the dry leaves, so dry leaves catch fire easily.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessExplain how COâ‚‚ is able to control fires.
CO2, being heavier than oxygen, covers the fire like a blanket. Since the contact between the fuel and oxygen is cut off, the fire is controlled. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
CO2, being heavier than oxygen, covers the fire like a blanket. Since the contact between the fuel and oxygen is cut off, the fire is controlled.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessName the unit in which the calorific value of a fuel is expressed.
The calorific value of a fuel is expressed in a unit called kilojoule per kg (kJ/kg). https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
The calorific value of a fuel is expressed in a unit called kilojoule per kg (kJ/kg).
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessGive reasons: Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminum pipe does not.
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not because the ignition temperature of paper is low as compare to the paper wrapped around an aluminium pipe. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not because the ignition temperature of paper is low as compare to the paper wrapped around an aluminium pipe.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessGive reasons: LPG is a better domestic fuel than wood.
LPG is a good fuel as compared to wood as it readily available and it is cheap. It burns easily in air at a moderate rate and it produces a large amount of heat. It does not leave behind any undesirable substances. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
LPG is a good fuel as compared to wood as it readily available and it is cheap. It burns easily in air at a moderate rate and it produces a large amount of heat. It does not leave behind any undesirable substances.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessGive reasons: Water is not used to control fires involving electrical equipment.
Water is not used to control fires involving electrical equipment because it may conduct electricity and harm those trying to douse the fire. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
Water is not used to control fires involving electrical equipment because it may conduct electricity and harm those trying to douse the fire.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See lessExplain how the use of CNG in automobiles has reduced pollution in our cities.
CNG produces very small amounts of harmful products like Sulphur dioxide, oxides of nitrogen, oxides of sulphur etc. CNG is a cleaner fuel. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
CNG produces very small amounts of harmful products like Sulphur dioxide, oxides of nitrogen, oxides of sulphur etc. CNG is a cleaner fuel.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-6/
See less