Q38. Why does cooking oil catch fire if a frying pan is kept on the burning stove for a long time?
Q39. What chemicals can put out a fire?
Q40. Why do you have to use paper or kerosene oil to start fire in wood or coal?
Q41. Explain why we are advised not to sleep in a closed room with a coal fire burning.
Why is it not advisable to sleep in a closed room with burning coal in the fireplace during winters?
Q42. Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not. Give reason.
Q43. How is fire caused by electricity extinguished?
Q44. What are inflammable substances? Give examples.
Q45. Which zone of a flame does a goldsmith use for melting gold and silver and why?
Q46. What is the colour of the different zones of a flame?
Q47. It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain.
Q48. What is spontaneous combustion? Give one example.
Q49. How does pouring water extinguish a fire?
Q50. What is explosion? Explain with the help of example.