Optics

The magnification of plane mirror is:
1. 1.0
2. Infinite
3. 0.0
4. 2.0
Virtual, erect and diminished image are the characteristic features of a:
1. Plane mirror
2. Biconcave mirror
3. Concave mirror
4. Convex mirror
How does the frequency of a beam of ultra-violet light change when it goes from air into glass?
1. None of these
2. Frequency decreases
3. Remains the same
4. Frequency increases
Where will the image be formed if the object is at the focus of the concave mirror?
1. At C
2. Beyond C
3. Infinity
4. Between C and F
A convex lens has a focal length of 40 cm. Calculate its power.
1. 6.6 D
2. 4.5 D
3. 3.5 D
4. 2.5 D
According to snell’s law, $n_{21} \times n_{12}$ = ?
1. 2.0
2. 0.0
3. $\frac{1}{2}$
4. 1.0
A convex lens is:
1. Thicker at the middle than at the edges
2. Of uniform thickness everywhere
3. Thicker at the edges than at the middle
4. Called a diverging lens
Which type of mirror is used in ophthalmoscope to examine throat and ear?
1. Convex
2. Reflecting mirror
3. Plane mirror
4. Concave
When two prism, one up and one down in contact receive white light. What is the colour of light that will emerge out?
1. Blue colour
2. Green colour
3. White colour
4. Red colour
If $f_{1}$ and $f_{2}$ are the focal lengths of two lenses, what is the relation for equivalent focal length?
1. $\frac{f_{1} + f_{2}}{f_{1} \times f_{2}}$
2. $\frac{2 (f_{1} + f_{2})}{2 f_{1} \times f_{2}}$
3. $\frac{2 f_{1} \times f_{2}}{f_{1} + f_{2}}$
4. $\frac{f_{1} \times f_{2}}{f_{1} + f_{2}}$
The far point of a healthy person is:
1. 0.15 m
2. 100 m
3. Infinity
4. 15 cm
A ray of light travelling in air fall obliquely on the surface of a calm pond. It will:
1. Deviate away from the normal
2. Deviate towards the normal
3. Turn back on its original path
4. Go into water without deviating from its path
The human eye forms the image of an object at its:
1. Cornea
2. Iris
3. Retina
4. Pupil
The far point of a myopic person is 80cm in front of the eye. Which type of lens is required to correct the problem?
1. Concave
2. Bifocal
3. Convex
4. Plane lens
The refractive indices of three media P, Q, R, are 1.73, 1.33 and 2.24 respectively. Arrange these media in increasing order of their optical density.
1. P, Q, R
2. Q, R, P
3. R, Q, P
4. Q, P, R
The inability among the elderly to see nearby objects clearly because of the weaking of the ciliary muscles is called:
1. Myopia
2. Far sightedness
3. Presbyopia
4. Near-sightedness
Light waves are:
1. Mechanical waves
2. Electrical waves
3. Electromagnetic waves
4. None of these
The muscles of the iris control the:
1. Focal length of the eye lens
2. Opening of the pupil
3. Optic nerve
4. Shape of the crystalline lens
The values of f and u for a concave lens are always:
1. None of these
2. Sometimes negative sometimes positive
3. Positive
4. Negative
The angle through which a ray of light turns on passing through a prism is called:
1. Angle of incidence
2. Angle of deviation
3. Angle of reflection
4. Angle of emergence
When do we say a person is colour blind?
1. When person cannot see in the dark
2. When person cannot see in the light
3. When person cannot differentiate between colours
4. All of these
Find the focal length of a convex mirror of radius of curvature 1 m.
1. 0.5 m
2. 1 m
3. 0.25 m
4. None of these
A converging mirror forms a real image of height 4 cm, of an object of height 1 cm placed 20 cm away from the mirror. Calculate the focal length of the mirror?
1. 16 cm
2. - 16 cm
3. 20 cm
4. - 20 cm
Light travels through water with a speed $2.25 \times 10^{8} m / s$ . What is the refractive index of water? (Speed of light in vaccum = $3 \times 10^{8} m / s$ )
1. 1.33
2. 0.75
3. 0.707
4. 1.5
Light travels from a rarer medium 1 to a denser medium 2. The angle of incidence and refraction are respectively $45 °$ and $30 °$ . What is the refractive index of medium 1 w.r.t medium 2?
1. $\sqrt{2}$
2. $\frac{\sqrt{2}}{2}$
3. $\frac{1}{\sqrt{2}}$
4. None of these
A pond of depth 20 cm is filled with water of refractive index $\frac{4}{3}$ . Calculate apparent depth of the tank when viewed normally.
1. 10 cm
2. 15 cm
3. 5 cm
4. 26.67 cm
Eye lens is a:
1. Double convex lens
2. Double concave lens
3. Piano convex lens
4. Piano concave lens
Which cell responds to colour of light?
1. Rod shaped cells
2. Cone shaped cells
3. Both type of cells
4. Neither of the two cells
Splitting of white light into seven colours on passing through a glass prism is called:
1. Reflection
2. Refraction
3. Scattering
4. Dispersion
White light is made up of:
1. Seven colours
2. Six colours
3. All colours
4. No colour

Optics

Quiz