Corrosion is a serious problem. Every year an enormous amount of money is spend to replace damaged iron. What step can be taken to prevent this damage ? What will learners infer from this passage ?

Why is damage to the ozone layer a cause for concern ? What steps are being taken to limit this damage ?

What steps can be taken to reduce pollution due to particulate matter from industries?

Read the passage and answer the following questions. Spinal cord extends from the back or the hind brain to the back of the lumbar region. It is almost cylindrical shape. The white matter is towards periphery white grey matter is towards the center of spinal cord. The role of spinal cord is in nervous control. Animals died as soon as spinal cord was damaged. 1. What is shape and location of spinal cord?

Following passage describes charcterstics of colloids. Answer the questions at the end of it. Lyophilic colloidal sols are much more stable than lyophobic colloidal sols. This is due to the extensive solvation of lyophilic colloidal sols, which forms a protective layer outside it and thus prevents it from forming associated colloids. Lyophillic colloidal sols also protect lyophobic colloidal sols from precipition by the action of electrolytes. This is due to formation of a protective layer by lyophilic sols outside lyophobic sols. Lyophilic colloidal sols are called protective sols. Gelatin (lyophilic) protects gold sol (lyophobic) from coagulaion on the addition of sodium chloride solution. Protective powers of different colloidal sols are measured in terms of 'gold number' (Zigmody). It is defined as the amount of protective sol in milligrams that prevents the coagulation of 10 mL of a given gold sol on adding 1 mL of 10 percent sodium chloride. Thus smaller the gold number of a lyophillic sol, the greater is the protective power. 0.025g of starch sol is required to prevent coagulation of 10ml gold sol when ImL of 10% Nacl solution is present. What is gold number of starch sol

Read the passage and answer the following questions. Spinal cord extends from the back or the hind brain to the back of the lumbar region. It is almost cylindrical shape. The white matter is towards periphery while grey matter is towards the center of spinal cord. The role of spinal cord is in nervous control. Animals died as soon as spinal cord was damaged. 3. What type of matter present at the centre?

Rahul's father wants to deposit some amount of money every year on the day of Rahul's birthday. On his 1^(st) birthday Rs.100, on his birthday Rs.300, on his 3^(rd) birthday Rs.600, on his birthday Rs.1000 and so on. What is the amount deposited by his father on Rahul's 15^(th) birthday?