Our Environment — Science STD 10 — Question

The power of a lens is, -2D. What is its focal length?

Name a fossil fuel other than coal and petroleum.

What are the reproductive organs in a flower?

Name the metal which is the poorest conductor of heat.

What job does the pupil of the eye do?

Calculate the potential difference between the two terminals of a battery if 100 J of work is required to transfer 20 C of charge from one terminal of the battery to the other.

Explain why, filament type electric bulbs are not power efficient.

State any one difference between autotrophic and heterotrophic modes of nutrition.

List any two properties of the elements belonging to the first group of the modern periodic table.

How is the working nuclear reactor of a power plant shut down in an emergency?