FORMULAE Cylinder Curved surface area of cylinder = 2Πrh Total surface area of cylinder = 2Πr(h + r) Volume of cylinder = Πr2h Cone Curved surface area of cone = Πrl Total surface...
Five measures to control industrial pollution in India are as follows: (i) Particulate matter in the air can be reduced by fitting smoke stacks to factories with electrostatic precipitators, fabric filters,...
Question: What is the basic principle of electric pen ? Explain how it can be used for writing. Answer: Electric charge on ions is used for writing with an electric pen. Method : (i) Take a filter...