Electricity — Science STD 10 — Question

1. Write the mathematical expression for Joule's law of heating.
2. Compute the heat generated while transferring 96000 coulomb of charge in two hours through a potential difference of 40V.

What are the qualities of an ideal source of energy?

Identify the type of reactions taking place in each of the following cases and write the balanced chemical equation for the reactions.

1. Zinc reacts with silver nitrate to produce zinc nitrate and silver.
2. Potassium iodide reacts with lead nitrate to produce potassium nitrate and lead iodide.

Is the position of a star as seen by us its true position? Justify your answer.

An object placed 20cm in front of a mirror is found to have an image 15cm.

1. In front of it,
2. Behind the mirror.

Find the focal length of the mirror and the kind of mirror in each case.

Explain why, more complex multicellular organisms cannot give rise to new organisms through regeneration.

A flash of lightning carries 10C of charge which flows for 0.01s. What is the current? If the voltage is 10MV, what is the energy?

The near-point of a person suffering from hypermetropia is at 50cm from his eye. What is the nature and power of the lens needed to correct this defect ? (Assume that the near-point of the normal eye is 25cm).

The end product of a process is ethanol and carbon dioxide with the release of energy. Name this process and write the pathway involved in the reaction.

Describe the process of respiration in State whether it is anaerobic respiration or aerobic respiration.