English Medium इयत्ता १० - CBSE Important Questions for Science

Both soap and detergent are some type of salts. What is the difference between them?

Describe in brief the cleansing action of soap.

Write the name and structure of a saturated compound in which the carbon atoms are arranged in a ring. Give the number of single bonds present in this compound.

State modern periodic law.

"The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it". Draw a flow chart showing determination of sex of a newborn to justify this statement.

Write the function of the following part of the human eye:- iris

What is a rainbow? Draw a labelled diagram to show the formation of a rainbow.

What is meant by homologous series of carbon compounds?

Name the human male reproductive organ that produces sperms and also secretes a hormone. Write the functions of the secreted hormone.

Describe in brief the structure of placenta

State the laws of refraction of light. Explain the term 'absolute refractive index of a medium' and write an expression to relate it with the speed of light in vacuum.

On what factors does the resistance of a conductor depend?

When you add sodium hydrogen carbonate to acetic acid in a test tube, a gas liberates immediately with brisk effervescence. Name this gas. Describe the method of testing this gas.

State the reason why carbon can neither form \[\ce{C^4+}\] cations nor \[\ce{C^4−}\] anions but forms covalent compound.

Why do soaps not form lather in hard water?

State the reason why carbon can neither form \[\ce{C^4+}\] cations nor \[\ce{C^4−}\] anions but forms covalent compound.

Name the parts of the human female reproductive system where

i. fertilisation takes place

ii. implantation of the fertilised egg occurs

"Birds have evolved from reptiles" State evidence to prove the statement.

Define the power of a lens.

A student places a candle flame at a distance of about 60 cm from a convex lens of focal length 10 cm and focuses the image of the flame on a screen. After that he gradually moves the flame towards the lens and each time focuses the image on the screen.  

(a) In which direction-toward or away from the lens, does he move the screen to focus the image?
(b) How does the size of the image change?
(c) How does the intensity of the image change as the flame moves towards the lens?
(d) Approximately for what distance between the flame and the lens, the image formed on the screen is inverted and of the same size?