Transparent glass, which disperses or concentrates light rays when passed through them by refraction, is known as a lens. The two types of lenses are the concave lenses and the convex lenses.
A concave lens is used to treat nearsightedness or myopia. Concave lenses have at least one surface curved inside. A concave lens is also known as a diverging lens.
Read more: Concave lens
Important Concave Lens Questions with Answers
1. Choose the right answer: myopia is also known as _____.
- Farsightedness
- Nearsightedness
Answer: b) Nearsightedness
Explanation: Nearsightedness or shortsightedness is also called myopia.
2. Concave lens ______.
- Diverges the straight beam of light
- Converges the straight beam of light
Answer: a) Diverges the straight beam of light
Explanation: Concave lens is also referred to as a diverging lens. This lens diverges a straight beam of light.
3. The point on the principal axis at the centre of the lens is known as ______.
- Pole
- Focus
- Optical centre
- Power
Answer: c) Optical centre
Explanation: Optical centre is the point on the principal axis located at the centre of the lens.
4. Concave lenses in indoor viewers are used to ______ the image.
- Maximise
- Minimise
Answer: b) Minimise
Explanation: Concave lenses in indoor viewers or peepholes are used to minimise the image.
5. A concave lens is commonly used in _____.
- Telescopes
- Microscopes
- Camera
- Flashlights
Answer: a) Telescopes
Explanation: The telescope features a concave lens.
6. Write the lens formula.
Lens formula is given 1/f=1/u+1/v.
7. Which lens is thicker at the centre and thinner at the edges?
- Plane lens
- Mirror
- Concave lens
- Convex lens
Answer: c) Concave lens
Explanation: Concave lens is thicker at the centre and thinner at the edges.
8. Symptoms of myopia are ______.
- Squinting
- Frowning
- Headaches
- All of the above
Answer: d) All of the above
Explanation: Myopia is associated with headaches, squinting, and frowning.
9. Which lens is known as the converging lens?
- Concave lens
- Convex lens
Answer: b) Convex lens
Explanation: Convex lens has the ability to converge the beam of light; hence it is known as the converging lens.
10. Which type of lens is used in the Magnifying glass?
- Concave lens
- Convex lens
Answer: b) Convex lens
Explanation: Convex lens is used in the magnifying glass since it lets an object appear larger than the actual.
Practice Questions
- What is a mirror?
- What is a lens?
- Define a concave lens.
- What is a convex lens?
- List five applications of a concave lens.