When ZnO is heated it turns yellow and returns back to original white colour on cooling. What could be the reason?

When you chew plain bread, chapati or bhakari for a long time, it tastes sweet. What could be the reason?

A cylindrical metallic rod in thermal contact with two reservoirs of heat at its two ends conducts an amount of heat Q in time t. The metallic rod is melted and the material is formed into a rod of half the radius of the original rod. What is the amount of heat conducted by the new rod, when placed in thermal contact with the two reservoirs in time?

Shreyas went to a garden on a wintry morning. When he came back,he found it difficult to breath and started wheezing.What could be the possible condition and how can he be treated?

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using.

Give scientific reasons: Copper sulphate crystals turn to a white amorphous powder on heating.

In Young's double slit experiment what will we observe on the screen when white light is incident on the slits but one slit is covered with a red filter and the other with a violet filter ? Give reasons for your answer .

Give scientific reasons for the following: When zinc granules are added to copper sulphate solution, the blue coloured solution turns colourless.

When a cross in made between tall plants with yellow seeds (TtYy) and tall plant with green seed (TtYy), what proportions of phenotype in the offspring could be expected to be : Tall and green

When a cross in made between tall plants with yellow seeds (TtYy) and tall plant with green seed (TtYy), what proportions of phenotype in the offspring could be expected to be : Dwarf and green.

A substance of mass m kg requires a power input of P watts to remain in the molten state at its melting point. When the power is turned off, the sample completely solidifies in time t s. What is the latent heat of fusion of the substance?