Q22. What are the three zones of flame?
Q23. What is combustion? Give example.
Q24. Why food is called fuel for our body?
Q25. Why is the innermost zone of a flame black in colour?
Q26. Explain how CO2 is able to control fires.
Q27. Which is the best fire extinguisher for fires involving electrical equipment and inflammable materials like petrol?
Q28. Why is water not used to control fires involving electrical equipment?
Explain why fire caused by electricity should not be extinguished by pouring water?
Why water is not suitable for extinguishing fire caused due to electrical appliances?
Why can we not use water to extinguish fire caused due to electrical appliances?
Q29. What are the harmful products released by the burning of fuels?
Q30. What is rapid combustion? Give one example.
Q31. Why are fires produced by burning oil not extinguished by pouring water?
Water is not suitable for fires involving oil and petrol. Explain.
The fire produced by petrol cannot be extinguished by using water. Explain why?
Q32. What causes global warming?
Q33. What are the effects of global warming?
Q34. What is combustible substance? Give some examples.
Q35. What is non-combustible substance? Give some examples.
Q36. Can you burn a piece of wood by bringing a lighted matchstick near it? Explain.
Q37. How forest fires occur during the hottest summer days?
Why do forest fires occur during hot summers?