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OTI365 - NTSE - X Standard
NTSE SAT Physics - Light Important Questions with Answer

NTSE SAT Physics - Light

Exam Duration: 45 Mins Total Questions : 30

1 )

To get three images of single object, one should have two plane mirrors at an angle of

(a)
45⁰
(b)
60⁰
(c)
90⁰
(d)
135⁰

2 )

A square wire of side 3.0 cm is placed 25 cm in front of a concave mirror of focal length 10 cm with its centre on the axis of the mirror and its plane normal to the axis. The area enclosed by the image of the wire is

(a)
7.5 cm²
(b)
6.0 cm²
(c)
4.0 cm²
(d)
3.0 cm²

3 )

The critical angle for a medium is 60°.What is the refractive index of a medium?

(a)
1.6
(b)
1.2
(c)
1.41
(d)
1.17

4 )

Two thin lenses are in contact and the focal length of the combination is 80 cm, If the focal length of one lens is 20 cm, then power of the other lens, will be

(a)
-1.00 D
(b)
4.00 D
(c)
1.66 D
(d)
-3.75D

5 )

The power of the lens whose focal length is 1m is

(a)
one dioptre
(b)
two dioptre
(c)
three dioptre
(d)
zero dioptre

6 )

The focal length of a simple convex lens used a magnifier is10 cm, at what distances, the object should be placed from the lens such that the image will be formed at least distance of distinct vision (D = 25 cm)

(a)
25/7
(b)
50/7
(c)
50/3
(d)
-50/7

7 )

If the angle between the incident ray and reflected ray is 40⁰, then angle of reflection is

(a)
80⁰
(b)
60°
(c)
20°
(d)
30°

8 )

The centre of curvature of a mirror in front of it

(a)
convex
(b)
concave
(c)
convex or concave
(d)
none of these

9 )

In hypermetropia image is formed

(a)
on the retina
(b)
in front of the retina
(c)
behind he retina
(d)
none of these

10 )

The light which deviate most while passing through a prism

(a)
red
(b)
violet
(c)
indigo
(d)
yellow

11 )

A concave mirror forms a real and enlarged image of an object if the object is placed at between

(a)
2F
(b)
F
(c)
F and C
(d)
F and P

12 )

The splitting of light into its component colours is called:

(a)
refraction
(b)
spectrum
(c)
dispersion
(d)
diffraction

13 )

The incident ray passing through the focus (F) of a mirror _______ after reflection.

(a)
Passes through C
(b)
Passes through F
(c)
Becomes parallel to the principal axis
(d)
Passes through the pole

14 )

We can see objects because of ____

(a)
Reflection
(b)
Refraction
(c)
Transmission
(d)
Diffraction

15 )

Real images formed by single convex lenses are always ______

(a)
On the same side of the lens as the object
(b)
Inverted
(c)
Erect
(d)
Smaller than the object

16 )

The focus of a concave mirror is

(a)
Real
(b)
Virtual
(c)
Undefined
(d)
At the pole

17 )

A converging mirror is known as ______

(a)
Convex mirror
(b)
Plane mirror
(c)
Concave mirror
(d)
Cylindrical mirror

18 )

Which of the following has the highest refractive index?

(a)
Glass
(b)
Water
(c)
Pearl
(d)
Diamond

19 )

In torches, search lights and headlights of vehicles the bulb is placed

(a)
between the pole and the focus of the reflector
(b)
very near to the focus of the reflector
(c)
between the focus and centre of curvature of the reflector
(d)
at the centre of curvature of the reflector

20 )

The laws of reflection hold good for

(a)
plane mirror only
(b)
concave mirror only
(c)
convex mirror only
(d)
all mirrors irrespective of their shape

21 )

At noon the sun appears white as

(a)
light is least scattered
(b)
all the colours of the white light are scattered away
(c)
blue colour is scattered the most
(d)
red colour is scattered the most

22 )

Which of the following statement is correct?

(a)
A person with myopia can see distant objects clearly
(b)
A person with hypermetropia can see nearby objects clearly
(c)
A person with myopia can see nearby objects clearly
(d)
A person with hypermetropia cannot see distant objects clearly

23 )

For a released eye, the magnification (m) of a compound microscope is

(a)
\(\frac{L}{f_0}\times\frac{D}{f_e}\)
(b)
\(\frac{L}{f_0}\times\frac{f_e}{D}\)
(c)
\(\frac{f_0}{L}\times\frac{D}{f_e}\)
(d)
\(\frac{f_0}{l}\times\frac{f_e}{D}\)

24 )

Mirage is produced in hot deserts due to

(a)
reflection
(b)
refraction
(c)
total internal reflection
(d)
dispersion

25 )

The incorrect ray diagram is diamond water

(a)
(b)
(c)
(d)

26 )

A lens of Il = 1.5 produces a virtual image of a real object in air. If the whole set up is immersed in water, the image will

(a)
Shift closer to lens
(b)
Shift a way from lens
(c)
remain in same point
(d)
depend on whether concave or convex len

27 )

The part of the eye which changes the focal length of the eye lens

(a)
Iris
(b)
Cornea
(c)
Pupil
(d)
Ciliary muscles

28 )

Which of the following diagrams shows correctly the refraction of light by a prism

(a)
(b)
(c)
(d)

29 )

A point object P moves towards a convex mirror with a constant speed V, along its optic axis. The speed of the image

(a)
is always < V
(b)
may be >, = or < V depending on the position of P
(c)
increases as P comes closer to the mirror
(d)
decreases as P comes closer to the mirror

30 )

An air bubble is inside water. The refractive index of water is 4/3. At what distance from the air bubble should a point object be placed so as to form a real image at the same distance from the bubble