Chapter 15 Light of Class 7 Science NCERT Book (PDF) is available here for download in PDF format. Chapter 15 of Class 7 Science NCERT Books is one of the important chapters and also one of the interesting chapters. Students are advised to learn this chapter and prepare for Class 7 Science exams.
A snapshot from the chapter:
Important concepts of the chapter:
⇒ Concave lens
⇒ Concave mirror
⇒ Convex lens
⇒ Convex mirror
⇒ Erect image
⇒ Magnified image
⇒ Magnifying glass
⇒ Real image
⇒ Rear view mirror
⇒ Side mirror
⇒ Spherical mirror
⇒ Virtual image
Important points of the chapter:
⇒ Light travels along straight lines.
⇒ Any polished or a shining surface acts as a mirror.
⇒ An image which can be obtained on a screen is called a real image.
⇒ An image which cannot be obtained on a screen is called a virtual image.
⇒ The image formed by a plane mirror is erect. It is virtual and is of the same size as the object. The image is at the same distance behind the mirror as the object is in front of it.
⇒ In an image formed by a mirror, the left side of the object is seen on the right side in the image, and right side of the object appears to be on the left side in the image.
⇒ A concave mirror can form a real and inverted image. When the object is placed very close to the mirror, the image formed is virtual, erect and magnified.
⇒ Image formed by a convex mirror is erect, virtual and smaller in size than the object.
⇒ A convex lens can form real and inverted image. When the object is placed very close to the lens, the image formed is virtual, erect and magnified. When used to see objects magnified, the convex lens is called a magnifying glass.
⇒ A concave lens always forms erect, virtual and smaller image than the object.
⇒ White light is composed of seven colours.