When two substances A and B are mixed together in a pestal and mortar, a large amount of heat is envolved and a new substances C is formed. C has the properties different from A and B. Is C an element , compound or a mixture ?

There are 5 routes from place A to place B and 3 routes from place B to place C. Find how many different routes are there from A to C via B.

Two system of rectangular axes have the same origin. If a plane cuts them at distance a, b, c and a', b', c' from the origin, then:

Two dice are rolled. Let A, B and C be the events of getting a sum 2, a sum 3 and a sum 4 respectively. Is event C compound ?

If x is a positive real number different from 1 such that log_a x, log_b x, log_c x are in A.P then

A brown substance 'A' on heating in air forms a substance 'B'. When hydrogen is passed over heated B, it changes back to A. Write chemical equations for the reactions.

A brown substance 'A' on heating in air forms a substance 'B'. When hydrogen is passed over heated B, it changes back to A. Name the chemical changes occuring during these processes.

A test charge q is moved without acceleration from A to C along the path from the point A to B and then from B to C in electric field as shown in fig. Calculate the potential difference between A and C.

A particular substance is being cooled by a stream of cold air (temperature of the air is constant and is 5^(@)C ) where rate of cooling is directly proportional to square of difference of temperature of the substance and the air. If the substance is cooled from 40^(@)C to 30^(@)C in 15 min and temperature after 1 hour is T^(@)C, then find the value of [T]//2, where [.] represents the greatest integer function.

A non-metal A is an important consituent of our food and forms two oxides B and C. Oxide B is toxic where as C causes global warming. Identify A,B and C?