Lens

Q.

How real image is different from virtual image?

Q.

Write any two differences between real image and virtual image.

Q. Which of the following statements is true?

1. Concave lenses are also called converging lenses.
2. Concave lenses can both converge and diverge the rays falling on them.
3. Convex lenses are also called converging lenses.
4. Convex lenses are also called diverging lenses.

Q.

A real image of an erect object is always inverted.

1. False

2. True

Q.

An object is placed infront of a lens. If we cover the middle part of the lens, the intensity of the image formed will decrease.

1. True

2. False

Q.

Virtual images

1. may or may not be projected on the screen.

2. cannot be projected on the screen.

3. projected on the eyes only

4. can be projected on the screen.

Q. Why is a thin lens preferred over a thicker one?

1. To increase the power of the lens.
2. To avoid reflection of light.
3. To remove wastage of glass.
4. To avoid lateral displacement of the light ray.

Q. Which of the following statements is true?

1. Concave lenses can both converge and diverge the rays falling on them.
2. Convex lenses are also called converging lenses.
3. Convex lenses are also called diverging lenses.
4. Concave lenses are also called converging lenses.

Q.

Which type of image can be obtained on screen?

1. Real image

2. Virtual image

3. Erect image

4. None of the above

Q.

Which lens should be used to burn a piece of paper?

1. Biconvex lens
2. Biconcave lens
3. Plano-concave lens
4. Plano-convex lens

Q. Which of the following is an appropriate condition for a thin lens?

1. None of these

2. Apparture < Radius of curvature

3. Apparture > Radius of curvature

4. Apparture = Radius of curvature