Convex Lens — Interactive NEET Physics Visual Lab
A convex (converging) lens bends parallel rays to a single principal focus. With the object placed beyond 2F, the ray parallel to the axis refracts through F and the ray through the optical centre goes straight — they cross to form a real, inverted, diminished image between F and 2F. Tap any part of the interactive ray diagram below to explore it, in plain English and with an exam-accurate NEET note.
Explore the convex lens — tap any part
Tap a structure to see what it does in plain English plus an exam-accurate NEET note, or hit Guided tour to be walked through it step by step.
Convex Lens
Ray optics
Selected structure
Convex Lens
A convex (converging) lens is thicker in the middle and bends parallel light inward to a single point. With the object placed beyond 2F, the two principal rays cross on the far side to form a real, inverted, diminished image. Tap any part, or take the guided tour.
NEET note
▸ All structures & functions
- Convex Lens
- A piece of glass that is thicker in the middle and bends parallel light rays inward so they meet at a point.
- NEET:A convex (converging) lens refracts parallel rays to meet at the principal focus; it has a positive focal length.
- Principal Axis
- The straight reference line running through the centre of the lens, at right angles to it.
- NEET:Principal axis: the line through the centres of curvature of the two surfaces, passing through the optical centre.
- Optical Centre (O)
- The exact middle of the lens — a ray aimed at it passes straight through without bending.
- NEET:Optical centre (O): a ray through it travels undeviated; all object and image distances are measured from O.
- Principal Focus (F)
- The point where rays coming in parallel to the axis meet after passing through the lens. There is one on each side.
- NEET:Principal focus (F): where parallel rays converge. 2F lies at twice the focal length and marks the image-formation cases.
- Object
- The upright arrow whose image the lens forms — here placed beyond 2F₁ on the left.
- NEET:Object beyond 2F₁: the case shown here, which produces a real, inverted and diminished image.
- Refracted Rays
- The two key rays — one parallel to the axis, one through the centre — that the lens bends together to fix the image.
- NEET:The ray parallel to the axis refracts through F; the ray through O passes straight. Their intersection locates the image.
- Real Image
- Where the bent rays actually cross and form a picture you could catch on a screen — upside-down and smaller here.
- NEET:Real, inverted and diminished image formed between F₂ and 2F₂ on the far side of the lens (object beyond 2F₁).
Convex Lens: structures & functions
A quick, exam-focused reference for every structure in the convex lens — each with a plain-English answer and the precise NEET point.
What is a convex lens?
A piece of glass that is thicker in the middle and bends parallel light rays inward so they meet at a point. A convex (converging) lens refracts parallel rays to meet at the principal focus; it has a positive focal length.
What is the principal axis?
The straight reference line running through the centre of the lens, at right angles to it. Principal axis: the line through the centres of curvature of the two surfaces, passing through the optical centre.
What is the optical centre of a lens?
The exact middle of the lens — a ray aimed at it passes straight through without bending. Optical centre (O): a ray through it travels undeviated; all object and image distances are measured from O.
What is the principal focus of a lens?
The point where rays coming in parallel to the axis meet after passing through the lens. There is one on each side. Principal focus (F): where parallel rays converge. 2F lies at twice the focal length and marks the image-formation cases.
Where is the object placed in this ray diagram?
The upright arrow whose image the lens forms — here placed beyond 2F₁ on the left. Object beyond 2F₁: the case shown here, which produces a real, inverted and diminished image.
Which rays are used to locate the image?
The two key rays — one parallel to the axis, one through the centre — that the lens bends together to fix the image. The ray parallel to the axis refracts through F; the ray through O passes straight. Their intersection locates the image.
What image does a convex lens form when the object is beyond 2F?
Where the bent rays actually cross and form a picture you could catch on a screen — upside-down and smaller here. Real, inverted and diminished image formed between F₂ and 2F₂ on the far side of the lens (object beyond 2F₁).
Frequently asked questions
What is a convex lens?
A piece of glass that is thicker in the middle and bends parallel light rays inward so they meet at a point. A convex (converging) lens refracts parallel rays to meet at the principal focus; it has a positive focal length.
What is the principal axis?
The straight reference line running through the centre of the lens, at right angles to it. Principal axis: the line through the centres of curvature of the two surfaces, passing through the optical centre.
What is the optical centre of a lens?
The exact middle of the lens — a ray aimed at it passes straight through without bending. Optical centre (O): a ray through it travels undeviated; all object and image distances are measured from O.
What is the principal focus of a lens?
The point where rays coming in parallel to the axis meet after passing through the lens. There is one on each side. Principal focus (F): where parallel rays converge. 2F lies at twice the focal length and marks the image-formation cases.
Where is the object placed in this ray diagram?
The upright arrow whose image the lens forms — here placed beyond 2F₁ on the left. Object beyond 2F₁: the case shown here, which produces a real, inverted and diminished image.
Which rays are used to locate the image?
The two key rays — one parallel to the axis, one through the centre — that the lens bends together to fix the image. The ray parallel to the axis refracts through F; the ray through O passes straight. Their intersection locates the image.
What image does a convex lens form when the object is beyond 2F?
Where the bent rays actually cross and form a picture you could catch on a screen — upside-down and smaller here. Real, inverted and diminished image formed between F₂ and 2F₂ on the far side of the lens (object beyond 2F₁).
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