Why don't birds sitting on live wire get electric shock?

Name two types of spherical mirror

Nidhi wanted the image of her pencil to be double the size of its original size. Name the mirror used for getting such image

Dead remains of two species A and B were buried. Later only Xs body was found to be a fossil but not B's given reason

Doctor advised a patient to take iodised salt. Explain why?

A patient is not able to balance his body and cannot walk properly by keeping the balance and cannot coordinate it. Name the part of brain which is affected.

A doctor advised a patient to take less sugar in her diet. Which disease is she suffering from?

A metal nitrate solution ‘A’ is added to reddish brown metal ‘B’. The metal present in ‘A’ is used for making jewellery and turns black in air, very thin foils of metal are used to decorate sweets. The compound ‘C’ formed on chemical reaction is blue in color and metal present in ‘A’ is formed. Identify A’ ‘B’ and ‘C’ and write chemical reactions involved.

Arun took a pale green substance X in a test tube, and heated it over a flame. He observed a color change along with evolution of two gases with the smell of burning sulphur
(a) Identify X.
(b) Identify the product formed.
(c) Write the equation.
(d) Identify the type of chemical reaction.

People living in coastal areas use plastic articles than iron articles for their day to day activities. Why?