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"Light" question number distribution across years
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JAMB questions for "Physics :: Light"
Q1
When an object is placed between the principal focus and the optical centre of a convex lens, it could be used as a
A
compound microscope
B
simple microscope
C
projector
D
reflecting lens
E

Light
Q2
The instrument used by designers to obtain different colour patterns is called
A
sextant
B
kaleidoscope
C
periscope
D
episcope
E

Light
Q3
The production of pure spectrum could easily be achieved using a
A
triangular prism only
B
triangular prism with two concave lenses
C
glass prism with a pin
D
triangular prism with two convex lenses
E

Light
Q4

A glass plate 0.9cm thick has a refractive index of 1.50 . How long does it take for a pulse of light to pass through the plate?

A

3.0 X 10-10s

B

3.0 X 10-11s

C

4.5 X 10-10s

D

4.5 X 10-11s

E

Light
Q5
The phenomenon of light bending round an obstacle is
A
reflection
B
diffraction
C
polarization
D
refraction
E

Light
Q6
An object placed 10cm from a concave mirror of focal length 5cm would have its image
A
B
at the centre of curvature
C
at infinity
D
10cm from the focus
E

Light
Q7
A person can focus objects when they lie beyond 75cm from his eyes. The focal length of the lens required to reduce his least distance of distinct vision to 25cm is
A
75.00cm
B
18.75cm
C
25.00cm
D
37.50cm
E

Light
Q8
Non luminous objects can be seen because they
A
emit light
B
are polished
C
are near
D
reflect light
E

Light
Q9
A submarine is observed to rise from a real depth of 80 m to 60 m in water. Calculate the change in apparent depth. [ Refractive index of water = 4/3 ]
A
45 m
B
60 m
C
80 m
D
15 m
E

Light
Q10
A real image three times the size of an object is formed 24 cm from a converging mirror. What is the focal length of the mirror ?
A
8 cm
B
16 cm
C
6 cm
D
12 cm
E

Light
Q11
A thin converging lens has a power of 4.0 diopters. Determine its focal length.
A
0.25m
B
0.03 m
C
5.00m
D
2.50 m
E

Light
Q12
The sharpness of the boundary of the shadow of an object is determined by the
A
rays of light passing through the object
B
intensity of light striking the object
C
opacity of the object
D
nature of the object
E

Light
Q13
The figure below shows a plot of angles of deviation through a glass prism when light is incident at &#952; degrees on the prism. The incident angle that produces the minimum deviation is
A
250
B
180
C
350
D
200
E

Light
Q14

In photoelectric effect, which of the following graphs correctly represents the graph of stopping potential V0 against frequency f of incident light?

A
B
C
D
E

Light
Q15
Fluorescent tubes produce light by the
A
excitation of gas molecules
B
conduction of solar energy
C
refraction of light by a gas molecules
D
thermal agitation of electrons in the tube
E

Light
Q16
What type of mirrors are capable of producing parallel beams of light such as those arising from the headlamps of a car?
A
Parabolic mirrors
B
Plane mirrors
C
Cylindrical mirrors
D
Spherical mirrors
E

Light
Q17
What happens to the rays in a parallel beam of light ?
A
They diverge as they travel
B
They intersect
C
They converge as they travel
D
They meet at infinity
E

Light
Q18
A ray of light makes an angle of 35° with a plane mirror. What is the angle of reflection ?
A
35°
B
55°
C
70°
D
65°
E

Light
Q19
A person can focus an object only when it lies within 200 cm from him. Which spectacles should be used to increase his maximum distance of distinct vision to infinity?
A
Convex lens
B
Binoculars
C
Concave lens
D
Plane glasses
E

Light
Q20
If u is the object distance and v the image distance , which of the following expressions gives the linear magnification produced by a convex lens of focal  length f?
A
u/f -f
B
u/v + f
C
v/f +1
D
v/f -1
E

Light
Q21
Calculate the angle of minimum deviation for a ray which is refracted through an equiangular prism of refractive index 1.4
A
60°
B
29°
C
99°
D
90°
E

Light
Q22
The refractive index of the medium M in the diagram below is
A
1&#8730;3
B
2&#8730;3
C
&#8730;3
D
2&#8730;3
E

Light
Q23
If an object is placed between two parallel plane mirrors with their reflecting surfaces facing each other, how many images of the object will be formed?
A
four
B
Two
C
Eight
D
Infinite
E

Light
Q24
By what factor will the size of an object placed 10cm from a convex  lens be increased if the image is seen on a screen placed  25cm from the lens?
A
2.5
B
1.5
C
0.4
D
15.0
E

Light
Q25
At what position will an object be placed in front of a concave mirror in order to obtain an image at infinity ?
A
At the centre of curvature
B
Between the principle focus and the centre of curvature
C
At the pole of the mirror
D
At the principal focus
E

Light
Q26
A ray incident on a glass prism undergoes minimum deviation when the
A
refraction angle equals 90°
B
incident angle is equal to the angle of refraction
C
incident angle is equal to the angle of emergence
D
incident angle equals 90°
E

Light
Q27
Which of the following pairs of light rays shows the widest separation in the spectrum of white light?
A
Green and Yellow
B
Indigo and violet
C
Orange and red
D
Blue and red
E

Light
Q28
A ray of light is incident on an equilateral triangular glass prism of refractive index 2/3.  Calculate the angle through which the ray is minimally deviated in the prism.
A
37.2°
B
48.6°
C
30.0°
D
42.0°
E

Light
Q29
The operation of an optical fibre is based  on the principle of
A
polarization of light
B
refraction of light
C
interference of light
D
dispersion of light
E

Light
Q30
Calculate the refractive index of the material for the glass prism in the diagram below
A
&#8730;2
B
3/2
C
&#8730;2/2
D
4/3
E

Light
Q31
A coin placed below a rectangular glass block of thickness 9cm and refractive index 1.5 is viewed vertically above the block. The apparent displacement of the coin is
A
8 cm
B
6 cm
C
5 cm
D
3 cm
E

Light
Q32
A ray of light which strikes a glass slab from air at normal incidence passes through the slab
A
deviated and undisplaced at a lower speed
B
undeviated and displaced at a faster speed
C
undeviated and undisplaced  at lower speed
D
deviated and displaced at a lower speed
E

Light
Q33
The colours seen in soap bubbles are due to
A
interference
B
dispersion
C
diffraction
D
refraction
E

Light
Q34
To produce an enlarged  and erect image with a concave mirror, the object must be positioned
A
between the principal focus and the centre of curvature
B
at the principal focus
C
between the principal focus and the pole
D
beyond the centre of curvature
E

Light
Q35
Which of the following eye defects can be corrected using a cylindrical lens?
A
Astigmatism
B
presbyopia
C
chromatic aberration
D
myopia
E

Light
Q36
A concave mirror of radius of curvature 40cm forms a real image twice as large as the object . The object distance is
A
30 cm
B
40 cm
C
60 cm
D
10 cm
E

Light
Q37
The eye controls the amount of light reaching the retina by adjusting the
A
retina
B
optic nerve
C
cornea
D
iris
E

Light
Q38
The driving mirror of a car has a radius of curvature of 1m. A vehicle behind the car is 4m from the mirror. Find the image distance behind the mirror
A
9/2
B
8/7
C
4/7
D
4/9
E

Light
Q39
A ray of light strikes a plane mirror at an angle of incidence of 35°. If the mirror is rotated through 10° through what angle is the reflected ray rotated?
A
20°
B
25°
C
45°
D
70°
E

Light
Q40
The terrestrial telescope has one extra lens more than the astronomical telescope . The extra lens is for
A
magnification of the image
B
erection of the image
C
improving the sharpness
D
creating an inverted image
E

Light
Q41
When a piece of rectangular glass block is inserted between two parallel plate capacitor, at constant plate area and distance of separation, the capacitances of the capacitor will.
A
decrease
B
increase
C
remain constant
D
decrease, then increase
E

Light
Q42
If a ray travelling in air is incident on a transparent medium as shown in the diagram, the refractive index of the medium is given as
A
sin &#945;/sin &#946;
B
sin &#946;/sin &#945;
C
cos &#945;/sin &#946;
D
cos &#946;/sin &#945;
E

Light
Q43
An engineer intends to deviate a light to deviate a light ray from its path by 120° through reflection from a plane mirror. Calculate the angle of incidence
A
20°
B
30°
C
40°
D
60°
E

Light
Q44
Total internal reflection occurs when light moves from
A
air to water
B
water to glass
C
a dense medium to a less dense medium
D
a less dense medium to a dense medium
E

Light
Q45
A boy observes a piece of stone at the bottom of a river 6.0m deep. If he looks from the surface of the river, what is the apparent distance of the stone from him?  ( Refractive index of water = 4/3)
A
4.5 m
B
5.0 m
C
5.5 m
D
8.0 m
E

Light
Q46
What optical instrument can best be constructed with converging lenses of focal lengths 50cm and 5 cm?
A
Compound microscope
B
Terrestrial telescope
C
Astronomical telescope
D
Galileo's telescope
E

Light
Q47
A projection lantern is used to  give the image of a slide on a screen . If the image is 24 times as large as the slide and the screen is 72.0m from the projecting lens, what is the position of the slide from the lens?
A
4.0 m
B
3.5 m
C
3.0 m
D
0.3 m
E

Light
Q48
In the diagram below, a beam of white light travels from a rare to a dense medium. What colours of light do the rays a, b and c respectively represent?
A
Blue, Yellow, and Red
B
Green, Red and Blue
C
Red, Green, and Blue
D
Yellow, Blue, and Red
E

Light
Q49
A man stands 4 m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is
A
3m
B
5 m
C
6 m
D
10 m
E

Light
Q50
The inside portion of part of a hollow metal sphere of diameter 20 m is polished . The portion will therefore form a
A
concave  mirror of focal length 5 cm
B
concave mirror of focal length 10cm
C
convex mirror of focal length 5 cm
D
convex mirror of focal length 20 cm
E

Light
Q51

The velocities of light in air and glass are 3.0 X 108 ms-1 and 2.0 x 108 ms-1 respectively . If the angle of refraction is 30°, the sine of the angle of incidence is

A

0.33

B

0.50

C

0.67

D

0.75

E

Light
Q52
An astronomical telescopes is said to be in normal adjustment when the
A
eye is accomodated
B
focal length of objective lens is longer than that of eye piece
C
final image is at the near point of eye
D
final image is at infinity
E

Light
Q53
The diagram below shows the prism arrangement in a
A
binocular
B
spectrometer
C
periscope
D
Projector
E

Light
Q54

The correct shape of the graph of uv against (u + v) for an object distance u and image distance v in an experiment to find the focal length of a convex lens is given as

A
B
C
D
E

Light
Q55
An object O lies at a distance m in front of a concave mirror of focal length f. If m < f, then the final image obtained will be
A
virtual and diminished
B
magnified and erect
C
real and inverted
D
diminished and erect
E

Light
Q56
The most suitable type of mirror used for the construction of a searchlight is the
A
concave mirror
B
convex mirror
C
spherical mirror
D
parabolic mirror
E

Light
Q57
An object is placed in front of two plane mirrors inclined at an angle of &#952;°. If the total number of images formed is 7, find the value of &#952;
A
30°
B
45°
C
51°C
D
90°
E

Light
Q58
The displacement d produced in a glass block of thickness t and refractive index n when an object is viewed through it is
A
t -n
B
t (1 + 1/n)
C
t (1 - 1/n)
D
t( 1/n - 1)
E

Light
Q59
A man wears convex lens glasses of focal length 30 cm in order to correct his eye defect . Instead of the optinum 25cm , his least distance of distinct vision is
A
14 cm
B
28 cm
C
75 cm
D
150 cm
E

Light
Q60
The colours seen in thin films of oil on the road and in soap bubbles are due to
A
reflection
B
interference
C
diffraction
D
polarization
E