JAMB - Physics (1983)

1
In a resonance tube experiment, a tube fixed length is closed at one end and several tuning forks of increasing frequency used to obtain resonance at the open end. If the tuning fork with the lowest frequency which gave resonance had a frequency f1 and the next tuning fork to give resonance had a frequency f2, find the ratio \(\frac{f^2}{f^1}\).
답변
(B)
3
2
Which of the following is NOT a vector quantity?
답변
(B)
Altitude
3
Which of the following statements about friction is NOT correct?
답변
(D)
The angle of friction is the angle between the normal reaction and the force of friction
4
The force with which an object is attracted to the earth is called its
답변
(C)
gravity
5
The refractive index of liquid is 1.5. If the velocity of light in vacuum is 3.0 x 108ms-1, the velocity of light in the liquid is
답변
(B)
2.0 x 10⁸m^-1
6
If relative density of a metal is 19, what will be the mass of 20cm3 of the metal when immersed in water?
답변
(A)
380g
7
Which of the following statements is true about liquid pressure is NOT correct? The pressure
답변
(E)
at a particular depth depends on the shape of the vessel
8
A ship travelling towards a cliff receives the echo of its whistle after 3.5 seconds. A short while later, it receives the echo after 2.5 seconds. If the speed of sound in air under the prevalling condition is 250ms ^-1, how much closer is the ship to the cliff?
답변
(B)
125m
9
which of the following is NOT correct? i. the pitch of a sound note depends on the frequency of vibrations. ii. the intensity of a sound note is proportional to the amplitude of vibrations. iii. beats are produced by two sources of sound because one wave is travelling faster than the other. iv. when two sources of sound of frequencies 500Hz and 502Hz are sounded together, a beat frequency of 2Hz is observed. v. the first harmonic of a tone have double the frequency of the fundamental note.
답변
(C)
i and iii
10
Which of the following statements about defects of vision is/are CORRECT? i. for a long sighted person, close objects appear blurred. ii. for a short sighted person, distant objects appear blurred. iii. short sight is corrected by using a pair of converging lenses.
답변
(C)
i and ii only
11
The range of wavelengths of the visible spectrum is 400nm - 700nm. The wavelength of gamma rays is
답변
(D)
shorter than 400nm
12
If the pressure on 100cm3 of an ideal gas is doubled while its kelvin temperature is halved, then the new volume of the gas will become
답변
(A)
25cm³
13
A train has an initial velocity of 44ms^-1 and an acceleration of -4ms^-1. Its velocity after 10 seconds is
답변
(B)
4ms^-1
14
Which of the following conditions are necessary and sufficient for total internal reflection to take place at the boundary between two optical media? i. light is passing from optically denser medium to optically less dense medium. ii. light is passing from optically less dense medium to optically denser medium. iii. angle of incidence is greater. iv. angle of incidence is lesser
답변
(D)
i and iii only
15
A man of mass 50kg ascends a flight of stairs 5m high in 5 seconds. If acceleration due to gravity is 10ms-2, the power expended is?
답변
(E)
500W
16
Which of the following arrangements in the sequence shown can be used to obtain a pure spectrum of white light?
답변
(A)
source, slit, converging lens, prism, converging lens, screen.
17
A milliameter with full scale deflection of 10mA has an internal resistance of 5 ohms. It would be converted to an ammeter with a full scale deflection of 1A by connecting a resistance of
답변
(B)
\(\frac{5}{99}\)ohms in parallel with it
18
The linear expansivity of brass is 2 x 10^-5 ^oC^-1. If the volume of a piece of brass is 10cm³ at 0^oC, what will be its volume at 100^oC?
답변
(C)
10.06cm³
19
A 24V potential difference is applied across a parallel combination of four 6-ohms resistor, The current in each resistor is
답변
(B)
4A
20
The electrochemical equivalent of a metal is 0.126 x 10^-6 kgC^-1. The mass of the metal that a current of 5A will deposit from a suitable bath in 1 hour is
답변
(E)
2.268 x 10 ^-3kg
21
Ripples on water are similar to light waves in that they both
답변
(E)
can be refracted and diffracted
22
A piece of wood is floating on water. The forces acting on the wood are
답변
(C)
weight and upthrust
23
Of the following derived units, the one that is not a unit of power is
답변
(C)
ampere²volt
24
a force of 16N applied 4.0kg block that is at rest on a smooth, horizontal surface. What is the velocity of the block at t = 5 seconds?
답변
(C)
20ms^-1
25
1,000 identical drops of oil of density 500kgm-3 have a total mass of 5 x 10-4kg. One of the drops forms a thin film of area 0.5m2 on water. The thickness of the film is
답변
(B)
2 x 10^-9m
26
The total length of a spring when a mass of 20g is hung from its end is 14cm, while its total length is 16cm when a mass of 30g is hung from the same end. Calculate the unstretched length of the spring assuming Hooke's law is obeyed.
답변
(B)
10.00cm
27
Which of the following statements is CORRECT? i. the mass number is equal to the total number of protons and electrons in an atom. ii. the atomic number is equal to the number of protons in an atom. iii. the number of electrons in an atom is equal to the total number of protons and neutrons in the nucleus.
답변
(B)
ii only
28
A short response to time is obtained in liquid-in-glass thermometer when the
답변
(E)
bulb is thin-walled and the liquid is a good conductor of heat
29
A machine has a velocity ratio of 5. It requires a 50kg weight to overcome a 200kg weight. The efficiency is
답변
(E)
80%
30
If the normal atmospheric pressure in a laboratory supports a column of mercury 0.76m high and the relative density of mercury is 13.8, then the height of water column which atmospheric pressure will support in the same laboratory at the same time is
답변
(B)
10m
31
An electric current of 3Aflowing through an electric heating elements of resistance 20 embedded in 1,000g of an oil raises the temperature of the oil by 10oC in 10 seconds then the specific heat capacity of the oil is
답변
(C)
0.18Jg^-1^oC
32
The difference of potential between the terminals of cells is 2.2 volts. When a 4ohm resistor is connected across the terminals of this cells, the potential difference is 2 volts. What is the internal resistance of the cell?
답변
(C)
0.40ohms
33
Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?
답변
(C)
heat \( \to \) kinetic\( \to \) electricity \( \to \) heat \( \to \) light
34
the speed of light in vacuum is 3.0 x 10⁸ms^-1. If the refractive index of a transparent liquid is \(\frac{4}{3}\), then the speed of light in the liquid is
답변
(B)
2.25 x 10 ⁸ms^-1
35
If the force of a charge of 0.2 coulomb in an electric field is 4N, then the electric field intensity of the field is
답변
(C)
20.0N/C
36
The specific latent heat of vaporization of a substance is always?
답변
(B)
greater than its specific heat of fusion
37
Longitudinal waves do not exhibit
답변
(D)
Polarization
38
Which of the following may be used to determine the relative humidity in a physics laboratory

I. Manometer
II. Wet-and-Dry Bulb Hygrometer
III. Hair Hygrometer
IV. A Hydrometer
답변
(B)
II and III Only
39
PQ is a thin rod on a horizontal table, RS is a plane mirror inclined at \( 45^{\circ}C\) to the horizontal as shown above. The image of PQ as seen in the mirror by the eye T is
답변
(B)
parallel to the mirror
40
the image above shows an inverted U-tube with the open end, O of one limb below the level, W of water in the tank, in order that water should begin to flow from the tank it is is necessary that
답변
(D)
The U-tube is completely filled with water and that P should be lower that W