In an experiment using a converging lens to produce real images on a screen, the linear magnification m, is plotted against the image distance v, as illustrated in the diagram below. The distance OP represents the
Afocal legth of the lens
Bthickness of the lens
Cradius of curvature of the lens
Ddiameter of the lens
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Question 2
waec2004
Which of the following representations is correct for an atom X with 28 electrons and 30 neutrons?
A\(^{30}_{28} X\)
B\(^{28}_{30} X\)
C\(^{58}_{30} X\)
D\(^{58}_{28} X\)
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Question 3
waec2004
A radioactive substance has a half-life of 3 days. If a mass of 1.55g of this substance is left after decaying for 15 days, determine the original value of the mass
A49.6g
B37.2g
C24.8g
D12.4g
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Question 4
waec2004
Which of the following statements about X-rays is not correct? They
Aare electromagnetic waves
Bcan be used to study crystal lattice
Ccan destroy living cells
Dare produced from the nucleus of an atom
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Question 5
waec2004
In which of the following devices is the principle of photoelectric effect not applicable?
Aclose-circuit television camera
Bburglar alarm
Csolar cells
Dperiscope
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Question 6
waec2004
An atom is normally electrically neutral because the
Anumber of electrons is equal to the number of protons
Bnumber of electrons is equal to the number of neutrons
Cnumber of protons is equal to the number of neutrons
Delectrons of the atom are buried deeply in the nucleus
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Question 7
waec2004
The main function of the mouth piece of a telephone is that it converts sound energy to
Amechanical energy
Belectrical energy
Cchemical energy
Dthermal energy
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Question 8
waec2004
Which of the following statements is not correct?
Aa magnetic field is a region in which a magnetic force will be detected
Ba magnetic line of force is a path along which a magnetic fields are scalar quantities it were free
Cmagnetic fields are scalar quantities
Dneutral point are obtained where the earth's magnetic force is exactly equal and opposite to that due to a magnet
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Question 9
waec2004
A charge of 1.6 x 10-10C is placed in a uniform electric field of intensity 2.0 x 105 NC-1. calculate the magnitude of the electric force exerted on the change
A3.2 x 105N
B1.8 x 105N
C3.2 x 10-5N
D1.8 x 10-5N
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Question 10
waec2004
Given that the gravitational constant is G. Newton's universal law of gravitation states that the force of attraction between two masses M1 and M2 separation by a distance r is
A\(Gr^2 M_1M_2\)
B\(Gr M_1M_2\)
C\(\frac{GM_1 M_2}{r^2}\)
D\(\frac{GM_1 M_2}{r}\)
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Question 11
waec2004
Calculate the energy stored in a 20\(\mu F\) capacitor. If the p.d between the plates is 40V
A3.2 x 10-2J
B1.6 x 10-2J
C8.0 x 10-4J
D4.0 x 10-4J
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Question 12
waec2004
The quantity of electric charge stored in a capacitor is measured in
Afarad
Bampere
Ccoulomb
Dvolt
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Question 13
waec2004
Find the cost of running a 60W lamp for 24 hours. If 1kW hr cost 5 naira
A14.4 naira
B12.5 naira
C7.2 naira
D2.0 naira
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Question 14
waec2004
A car fuse marked 3A operates optimally on a 12V battery, calculate the resistance of the fuse
A36.0\(\Omega\)
B15.0\(\Omega\)
C9.0\(\Omega\)
D4.0\(\Omega\)
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Question 15
waec2004
Which of following functions is performed by manganese IV oxide in the Lenclanche cell?
Acontrol of local action
Bdepolarisation of the cell
Cregulating current flow in the cell
Dreduction of the internal resistance of the cell
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Question 16
waec2004
Charges on a conductor are
Aevenly distributed over a surface of any shape
Bconcentrate on the inner surface of the conductor
Cconcentrate at the outer flat surface of the conductor
Dgenerally concentrated at sharply curved surface
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Question 17
waec2004
The sound from a vibrating tuning sound is when the tip of its stem is placed on a wooden table than when in air because
Athe friction between the table and the tuning fork generates additional energy
Bair molecules obsorb sound wave but wood transmit sound waves
Cthe table increases the frequency of the turning fork
Da large mass of air is set into vibration by the table
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Question 18
waec2004
Which of the following reasons explains why the walls and ceilings of a standard concert hall are usually covered with perforated pads? To
Aincrease the intensity of sound waves
Bincreases the loudness of the sound waves
Creduce the effect of revibration of sound waves
Ddecreases thr frequency of sound waves
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Question 19
waec2004
A girl stand 80m away from a tall cliff and blows a whistle. If the speed of sound in air is 330ms-1, how long would it take for her to hear the echo of the sound?
A2.062s
B0.970s
C0.485s
D0.242s
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Question 20
waec2004
A magnified and virtual image of a near object is produced by
