PART - 1 CH - 4 Carbon and Its Compounds — Science STD 10 — Question

An object 5.0 cm in length is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position of the image, its nature and size.

Vishva noticed in a dhaba around 50 bulbs, each of 100 W all were glowing. She calculated the cost of electricity consumed in one hour and told the dhaba owner to reduce the expenses and at the same time save electricity by using CFL bulbs instead of ordinary filament-type bulbs.
(1) What would be the cost of electric energy if 50 bulbs, each of 100 W , are used for one hour? 1 unit costs ₹ 5 .
(2) What is a CFL?
(3) What value did Vishva display in the above case?

Give the balanced chemical equations for the following:
(i) Reaction used in black and white photography
(ii) Reaction of oxidation of glucose
(iii) Formation of water from H₂ and O₂

Explain about refractive index in detail.

How the pollution caused by burning fossil fuels can be reduced?

What are the differences between the transport of materials in xylem and phloem?

Give scientific reason:
The characters are under the control of genes.

Explain Reflex action in detail.

Explain with appropriate diagram Newton's experiment showing that white light of the Sun (sunlight) is composed of seven colours.