ray optics(review till lens makers formula)

The focal length of a converging lens are f_V and f_R for

violet and red light respectively. Then

• f_V > f _R

• f_V = f _R

• f_V < f _R

• any of the three is possible depending on the value of

  the average refractive index m

Which of the following is not due to total internal reflection?

• Working of optical fibre

• Difference between apparent and real depth of pond

• Mirage on hot summer days

• Brilliance of diamond

Critical angle of light passing from glass to water is minimum for

• red colour

• green colour

• violet colour

• yellow colour

A ray of light travelling in a transparent medium of refractive index , falls on a surface separating the medium from air at an angle of incidence of 45°. For which of the following value of the ray can undergo total internal reflection?

• refractive index =1.33

• refractive index =1.40

• refractive index =1.50

• refractive index =1.25

A glass lens is immersed in water. What will be the effect on the focal length of lens?

• increases

• decreases

• remains constant

• answer does not depend upon the medium

Light of wavelength 6000 Å falls on plane mirror. The wavelength of reflected light

• increase

• decreases

• remains constant

• data is not sufficient to answer

an air bubble inside water behaves as

• converging lens

• Diverging lens

An equiconvex lens of focal length 12 cm is cut into two halves as shown in figure. Find the focal length of each part?

• -24 cm

• 24 cm

• 12 cm

• -12 cm

The line A & B in the ray diagram of figure represent a _______________ lens.

• converging

• Diverging

If refractive index of water is 4/3 and that of glass is 3/2 ,then refractive index of water w.r.t. glass is 9/8.

• True

• False