How far from a hill should a boy stand to hear the echo of his clap 1 .6s later? [Speed of sound in air is 340ms-1]
A186m
B272m
C544m
D1088m
E2000m
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Question 22
neco2004
Which of the following conclusion(s) can be drawn from Newton’s second law of motion? Force is proportional to
I. the product of mass and acceleration
II. the product of mass and velocity
III. Impulse
AI only
BII only
CIII only
DII and III only
EI, II and III
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Question 23
neco2004
A voltage supply of 12V r.m.s. and frequency 90Hz is connected to a 4 ω resistor. Calculate the peak value of the current
A48.8 A
B30.0 A
C27.5 A
D4.2 A
E3.0A
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Question 24
neco2004
The general equation of a wave CANNOT be written as
Ay = A Sin [2 π (\(\frac{t}{T}\) ± Xλ)]
By = A Sin [wt ± kx]
Cy = A Sin [2 \(\frac{\pi}{\lambda}\) (vt ± x)]
Dy = A Sin [2π (ft ± \(\frac{X}{\lambda}\) )]
Ey = A Sin 2 π f(T ± \(\frac{X}{\lambda}\))]
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Question 25
neco2004
Which of these expresses the relationship between the earth’s magnetic field FE, and the field’ FB due to a magnet at neutral points? FE is
Aequal and opposite to FB
Bequal to and in the same direction with FB
Cgreater than and in the same direction with FB
Dgreater than and opposite to FB
Eless than and opposite to FB
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Question 26
waec2004
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 27
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 28
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 29
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 30
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 31
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 32
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 33
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 34
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 35
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 36
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 37
waec2004
The quantity of electric charge stored in a capacitor is measured in
Afarad
Bampere
Ccoulomb
Dvolt
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Question 38
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 39
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 40
waec2004
Which of following functions is performed by manganese IV oxide in the Lenclanche cell?
