Lenses
Physics ⇒ Light and Optics
Lenses starts at 8 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Lenses.
How you perform is determined by your score and the time you take.
When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 10
A lens forms an image that is real, inverted, and the same size as the object. Where is the object placed?
A lens forms an image that is virtual, erect, and smaller than the object. What type of lens is it?
A lens has a focal length of 20 cm. What is its power in diopters?
A lens has a power of -2 D. What type of lens is it?
A lens is used as a magnifying glass. What type of lens is it?
A student places an object 10 cm from a convex lens of focal length 15 cm. Where will the image be formed?
A student uses a lens to project an image of a distant tree onto a screen. The image is real and inverted. What type of lens is being used?
Describe what happens to the image formed by a convex lens as the object moves from infinity towards the lens.
Explain why a convex lens is called a converging lens.
If a lens has a focal length of 50 cm, what is its power?
If an object is placed at 2F in front of a convex lens, where will the image be formed?
If the focal length of a lens is -25 cm, what is its power?
If the image distance (v) is +30 cm and the object distance (u) is -20 cm, what is the focal length (f) of the lens?
If the object distance is -30 cm and the image distance is +15 cm, what is the focal length of the lens?
State the lens formula relating object distance (u), image distance (v), and focal length (f).
What is the effect of increasing the curvature of a convex lens on its focal length?
What is the effect of using a lens with a shorter focal length in a camera?
What is the optical center of a lens?
What is the principal axis of a lens?
What is the sign convention for the focal length of a convex lens?
