GEOMETRICAL OPTICS

A hollow convex lens of glass will behave like

• convex lens

• concave lens

• glass plate

• mirror

Angle of minimum deviation is equal to the angle of prism A of an equilateral glass prism . The angle of incidence at which minimum deviation will be obtained is : __________

• 60⁰

• 30⁰

• 45⁰

• sin^-1(2/3)

A concave lens forms the image of an object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. The focal length of the lens will be : __________

• 8.6 cm

• 6.2 cm

• 10 cm

• 4.4 cm

The angle of incidence for an equilateral prism is 60⁰. What should be the refractive index of prism so that the ray is parallel to the base inside the prism?

• 1.414

• 1.732

• 1.33

• 9/8

If the distances of an object and its virtual image from the focus of a convex lens of focal length f are 1 cm each, then f is _______________

• 4 cm

• (√2 +1) cm

• 2√2 cm

• ( 2 + √2 ) cm

A ray of light is incident on a glass sphere of refractive index 1.5 . What should be the angle of incidence so that the ray which enters the sphere does not come out of the sphere?

• Tan^-1(2/3)

• sin^-1(2/3)

• 90⁰

• cos^-1(2/3)

When a ray of light enters a glass slab from air

• its wavelength decreases

• its wavelength increases

• its frequency increases

• neither its wavelength nor its frequency changes.

Tags

NGSS.HS-PS4-1

A real image is formed by a a convex lens, then it is put in contact with a concave lens and again a real image is formed. This image is : ______________

• shift towards the lens system

• shift away from the lens system

• remain in its original position

• shift to infinity

When an object is at distances x and y from a lens, a real image and virtual image respectively having same magnification. The focal length of the lens is : __________-

• ( x + y ) / 2

• x - y

• √xy

• x + y

A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. the power of the combination is : ______

• - 1.5 D

• -6.5 D

• + 6.5 D

• + 6,67 D