Category Archives: Class 10

Class 10 articles

Reflection and refraction good questions

Q1. What is the difference between reflection and refraction?
Q2.Refraction is caused by
a. different wave speeds.
b. more than one reflection.
c. displaced images.
d. bending.

Q3. What will happen to ray of light when it travels from rarer medium to a denser medium ?

Q4. What is absolute refractive index ?
Q5. If refractive index of glass is 1.65, What is the speed of light in glass. ?

CBSE Board and CCE FAQ -I

Question: Is it compulsory to appear in theory and practical papers in the compartment examination
Asnwer: In case the candidate has passed in the practical in the main examination, he/she is allowed to appear in the theory part only, and marks in the practical exam obtained at the main examination are carried forward and accounted for. In case a candidate has failed in the practical exam he/she shall have to appear in the theory and practical examination both irrespective of the fact that he/she has already cleared the theory examination

Mirror and Lens Overview And Problems

Glossary of Mirror and Lenses

Plane Mirror
A plane mirror is a mirror with a planar reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence.It always form virtual image

Concave or Converging Mirrors
A curved mirror that has its center farther away from you than its edges is called a concave mirror. A concave mirror tends to reflect parallel rays through a point called its focus – in other words a concave mirror converges light. Therefore concave mirrors are often referred to as converging mirrors. This converging effect makes sense if you imagine a concave mirror to be an array of small plane mirrors.You can demonstrate the converging of parallel light rays by a concave mirror quite dramatically for yourself. A relatively small concave mirror placed in the sun will gather enough light to ignite a small piece of paper quite quickly

Convex or Diverging Mirrors

The Age of the Universe( Big Bang)

One question has always fascinated the scientists ” When the universe began?” . Current Thinking believes that Universe began as a singularity in space and Time. The singularity is called as Big Bang. It is believed at this time everything was condensed into very small space. After that the Universe has been continuously expansion mode.

A Astronomer Edwin Hubble discovered in 1929 the rate of expansion of Universe i.e the rate at which the galaxies are receding from each other. That law is called Hubble Law. As per Law, if the two galaxies are at distance R,Their present relative velocity of separation is given by