Lenses and lasers

Question 1 of 10

The power of a lens of focal length 0.5 m is

Question 2 of 10

What is the power of a converging lens of focal length 25 cm?

Question 3 of 10

A converging lens forms a real image of an object at twice its focal length. The image is

Question 4 of 10

Laser light differs from ordinary light because it is

Question 5 of 10

A lens of power −2.5 D is

Question 6 of 10

A camera lens forms an image on the sensor that is

Question 7 of 10

A magnifying glass is a

Question 8 of 10

Two thin lenses of focal lengths 20 cm and 30 cm in contact have a combined focal length of

Question 9 of 10

An object is 30 cm from a converging lens of focal length 10 cm. The image distance is

Question 10 of 10

The magnification of an image formed 60 cm from a lens when the object is 20 cm away is