1992 - JAMB Physics Past Questions and Answers - page 5
41
A note is the octave of another note if it has
A
a frequency twice that of the first note
B
frequency half that of the first note
C
the same fundamental frequency as the first one
D
a frequency frequency eight times that of the first note
correct option: a
Users' Answers & Comments42
What is the frequency of the sound made by a siren having a disc with 32 holes and making 25 revolution per seconds?
A
80Hz
B
600Hz
C
800Hz
D
1600Hz
43
Which of the following properties make the convex mirror useful as a driving mirror? i. the image is real. ii. the image is erect. iii. it has a wide field of view. iv. the image is magnified.
A
i, ii, and iv
B
i, ii, iii
C
ii and iii
D
i and iii
correct option: c
Users' Answers & Comments44
When an object is placed very close to the pole of a concave mirror, the virtual image obtained is
A
diminished and upright
B
diminished and inverted
C
enlarged and inverted
D
enlarged and upright
correct option: d
Users' Answers & Comments45
A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three times the size of the object?
A
12cm
B
24cm
C
48cm
D
108cm
correct option: b
F = \(\frac{uv}{u + v}\)
v = 3u
18 = \(\frac{3u \times u}{3u + u}\)
u = 24cm
Users' Answers & Commentsv = 3u
18 = \(\frac{3u \times u}{3u + u}\)
u = 24cm
46
Which of the following statements is CORRECT about a long-sighted boy who does not put on glasses?
A
He cannot see distant objects clearly
B
Rays of light from a close object are focused in front of his retina
C
His eye ball is too long
D
Parallel rays of light are focused behind his retina
correct option: b
Users' Answers & Comments47
The speed of light in air is 3 x 108ms-1. What is the speed in glass with a refractive index of 1.50?
A
1.5 x 108ms-1
B
3.0 x 108ms-1
C
2.0 x 108ms-1
D
6.0 x 108ms-1
48
If the refractive index of a medium in air is 2.0, what is the critical angle for this medium?
A
30o
B
42o
C
45o
D
50o
correct option: a
sin c = \(\frac{1}{n}\) = \(\frac{1}{2}\)
c = sin-1\((\frac{1}{n})\)
= 30o
Users' Answers & Commentsc = sin-1\((\frac{1}{n})\)
= 30o
49
Which of the following arrangements of the components of electromagnetic spectrum is in ascending order of wavelengths?
A
Gamma rays, ultraviolet rays, X- rays, infra - red rays
B
Gamma rays, X-rays, ultraviolet rays, infra-red rays
C
infra-red rays, ultraviolet rays, X-rays, gamma rays
D
Gamma rays, ultraviolet rays, infra-red rays, X-rays
correct option: b
Users' Answers & Comments