Telscope is used to provide angular magnification of distant objects. Write any two advantage of reflecting type tele scope over refracting type telescopes.

Telscope is used to provide angular magnification of distant objects. Draw the ray diagram of a refracting type telescope when it is in normal adjustment.

Fuel cells are special type of galvanic cells. Write any two advantages of fuel cells

Write any two characteristics of each of the above two types of adsorption.

There are mainly two types of adsorption of gases on solids.Write any two characteristics of each of the above two types of adsorption.

Van der Waal's forces are attraction inter molecular forces. Write the names of any two types of van der Waal's forces.

A factory produces three items P,Q and R at two plants A and B . The number of items produced and operating costs per hour is as follows: It is desired to produce at least 500 items of type P , at least 400 items of type Q and 300 items of type R per day. Write the objective function and constraints.

Nucleophilic substitution reactions are of two type - S_N^1 reaction and S_N^2 reaction.Write any two reasons for the less reactivity of aryl halides towards nucleophil subsitution reactions.

Physisorption and chemisorption are the two types of adsorption. Write any four differences between them.