Metals and Non-Metals — Science STD 10 — Question

The number of malaria patients in a village increased tremendously when large number of frogs were exported from the village. What could be the cause for it?

Christmas tree lamps are usually wired in series. What happens if one lamp breaks?

Name two organisms which are now extinct and studied from their fossils.

Why does-the colour of copper sulphate solution change when an iron nail is kept immersed in it?

Suppose a coil is place in a changing magnetic field and the circuit is not closed will the current induce in the coil?

Define the principal focus of a concave lens.

Write an equation of the reaction of iron with steam. Indicate the physical states of all the reactants and products.

What type of image is formed:

1. In a plane mirror?
2. On a cinema screen?

Which is the real bleaching agent present in bleaching powder?

What type of plants reproduce by sexual reproduction method?