Microorganisms:Friends or Foe Online quiz

Microorganisms:Friends or Foe
NCERT Class VIII chapter 2(Science) 


Comments

Post a Comment

Popular posts from this blog

Friction NCERT Science Class 8 Chapter 12 Summary Note

Friction The force that opposes the relative motion between two surfaces in contact, is called friction.  Factors affecting friction Weight of object  Nature of surfaces in contact More the weight of object, more the friction.  More smooth surface experience less friction.  Importance of friction Friction helps in stopping object Friction helps to write, walk,  Friction helps in all activities Friction produces heat.  Harm cause by Friction Sole of shoes wear out.  Machine parts get wear out.  Friction can be increased by making surfaces rough. ( More rough means more interlocking between surfaces which means more friction )  Friction can be decreased by applying lubricant on surfaces.  Friction can be decresed by changing shape of object.  Rolling friction The force that oppose motion of rolling object, is rolling friction.  Sliding friction The force that oppose moti...
Read more

Materials: Metals and Non-metals Class 8 Science Chapter 4

Materials: Metals and Non-metals * Lustre -    Lustre is physical property of substance by    which it looks shiny. * Malleability -    Malleability is property of metal, by which    they can be beaten into thin sheets. * Ductility -    Property of metal, by which they can be    drawn into wires, is called ductility. * Good conductor of heat/electricity    -The materials through which heat/electricity    can pass, is called good conductor of    heat/electricity.    -Example- Iron. * Poor conductor of heat/electricity    -The materials through which heat/electricity      cannot pass, is called poor conductor of      heat/electricity.    - Example- Plastic * Sonorous -    Metals are sonorous since they produce    ringing sound. * Physical properties of metals and Non-    metals ...
Read more

Light NCERT Science Class 8 Summary Note

Image
What Makes Things Visible   When light from an object enters our eyes, then we see the object.  The light may have been emitted or reflected by the object.  Mirror   Highly polished surface is called mirror.  Reflection Bending back of light ray after falling on a surface, is called reflection.  Incident ray The light ray which strikes any surface, is called incident ray.  Reflected ray  The ray that comes back from the surface after reflection, is called as reflected ray.  Normal Line perpendicular to surface at point of incidence of light ray, is called normal.  Angle of incidence The angle between normal and incident ray, is called angle of incidence.  Angle of reflection The angle between normal and reflected ray, is called angle of reflection.  Laws of reflection (i) The incident ray, the normal at the point of incidence and the reflected ray, all lie in the same plane.  (ii) The angle of incidence is always equal to ...
Read more