Ray Optics(Rafraction of Light)

A 25.0 m object is placed 30.0 m from a convex lens, which has a focal length of 5.0 m. What is the distance of the image?

• 6 m

• 7 m

• 8 m

• 9 m

Which figure represents the path light takes through a converging lens?

• 
• 
• 
• 

A hollow convex lens of glass will behave like

• convex lens

• concave lens

• glass plate

• mirror

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

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

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

A student placed a pencil in a cup of water.  The pencil appears broken because light-

• always travels in a straight line
• bends when it passes through water
• makes the water in the glass evaporate
• reflects the pencil on the water's surface

Tags

NGSS.MS-PS4-2

We combine two lenses, one is convex and other is concave having focal lengths /, and f2 and their combined focal length is F. Combination of the lenses will behave like concave lens, if

• f1 > f2

• f1 = f2

• f1 < f2.

• f1 ≤ f2

The focal length of a biconvex lens of radii of each surface 50 cm and refractive index 1.5, is

• 40.4 cm

• 75 cm

• 50 cm

• 80 cm

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will

• become zero

• become infinite

• become small, but non-zero

• remain unchanged