2012 - JAMB Physics Past Questions and Answers - page 3
21
The equation of a wave traveling in a horizontal direction is expressed as y = 15 sin 2/5 (60t - x) what is its wave length?
A
60m
B
15m
C
5m
D
2m
22
Which of the following factors will affect the velocity of sound?
A
An increase in the pitch of the sound
B
An increase in the loudness of the sound
C
Wind travelling in the same direction of the sound
D
A change in the atmospheric pressure at constant temperature
correct option: c
Users' Answers & Comments23
The characteristic of a vibration that determines its intensity is the
A
Frequency
B
Overtone
C
Wavelength
D
Amplitude
correct option: d
Users' Answers & Comments24
Where can a man place his face to get an enlarged image when using a concave mirror to shave?
A
Between the centre of curvature and the principal focus
B
At the principal focus
C
Between the principal focus and the pole
D
At the centre of curvature
correct option: c
Users' Answers & Comments25
A pinhole camera is placed 300m in front of a building so that the image is formed on a screen 5cm from the the pinhole. If the image is 2.5cm high, the height of the building will be
A
25m
B
50m
C
100m
D
150m
correct option: d
==> \(\frac{v}{u}\) = \(\frac{hi}{ho}\)
==> \(\frac{5}{300}\) = \(\frac{2.5}{ho}\)
= 150m
Users' Answers & Comments==> \(\frac{5}{300}\) = \(\frac{2.5}{ho}\)
= 150m
26
The magnification of an object 2cm tall when placed 10cm in front of a plane mirror is
A
6.0
B
1.0
C
0.7
D
0.6
27
After reflection from the concave mirror, rays of light from the sun converges
A
at the radius of curvature
B
at the focus
C
beyond the radius of curvature
D
between the focus and radius of curvature
correct option: b
Users' Answers & Comments28
A glass block of thickness 10cm is placed on an object. If an observer views the object vertically, the displacement of the object is
A
3.33cm
B
5.00cm
C
6.67cm
D
8.50cm
correct option: a
\(\mu\) = R.9 = 1.5 = 10
A.P A.d, Ad = 6.66
Displacement = R.d - A.d = 10 - 6.66
= 3.33
Users' Answers & CommentsA.P A.d, Ad = 6.66
Displacement = R.d - A.d = 10 - 6.66
= 3.33
29
I. Rays of light travel from a less dense medium to a denser medium. II. The Angle of incidence is greater than critical angle. III. Rays of light travel from a denser medium to a less dense medium. Which of the statements above are conditions for total internal reflection to occur?
A
I & II only
B
I & III only
C
II & III only
D
II only
correct option: c
Users' Answers & Comments30
The use of lenses is Not applicable in the
A
projector
B
human eye
C
periscope
D
telescope
correct option: c
Users' Answers & Comments