A work of 30 joules is done is transferring 5 millicoulombs of charge from a point B to a point A in an electric Held. The potential difference between B and A is
A1.7 x 10-4V
B3.4x10-4V
C1.5x10-1V
D6.0 x103V
E1.2 x104V
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Question 12
waec1990
What is the electric potential energy between two protons each of charge q and at a distance of r apart? (Permittivity of free space = εo)
A4πεoq2r
Bqr/4πεo
Cq/4πεor
Dq2/4πεor
Eq2/4πεo
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Question 13
waec1990
Calculate the current in the 3Ω resistor shown in
the diagram above.
A3.0A
B4.0A
C4.3A
D12.0A
E39.0A
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Question 14
waec1990
Given that the gravitational constant is 7 X 10-11 Nm2kg-2, what is the force of attraction between 106kg mass of lead hanging one metre away from a 103kg mass of iron?
A7 x10-20N
B7 x 10-5N
C7x10-2N
D7x103N
E7x100N
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Question 15
waec1990
Which of the following pairs of light rays shows the widest separation in the spectrum of white light?
AYellow and red
BOrange and green
CViolet and blue
DBlue and green
ERed and indigo
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Question 16
waec1990
A simple microscope forms an image twice the size of the object. If the focal length of the lens of the microscope is 20m, how far is the object from the lens?
A10m
B20m
C30m
D40m
E60m
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Question 17
waec1990
The eye defect illustrated by the diagram above is
Aastigmatism
Blong sightedness
Closs accommodation
Dshort sightedness
Ecolour blindness
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Question 18
waec1990
The eye defect illustrated by the diagram above is
Aastigmatism
Blong sightedness
Closs accommodation
Dshort sightedness
Ecolour blindness
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Question 19
waec1990
The diagram above shows an incident ray A, inclined at angle of 50º to the interface CB. The ray OB is found to lie along the surface. What is the refractive index of the medium X with respect to air?
Asin50o/sin40o
Bsin40osin50o
Csin90o/sin50o
Dsin40o/sin90o
Esin90o/sin40o
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Question 20
waec1990
The diagram above shows an incident ray A, inclined at angle of 50o to the interface CB. The ray OB is found to lie along the surface. What is the refractive index of the medium X with respect to air?
Asin50o/sin40o
Bsin40osin50o
Csin90o/sin50o
Dsin40o/sin90o
Esin90o/sin40o
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Question 21
waec1990
A parallel beam of light is to be obtained from the headlamp ofa car. At which of the following positions should the source of light be placed from the pole of its spherical minor?
AAt the focal point
BAt the centre of curvature
CBeyond the centre of curvature
DBetween the focal point and the pole
EBetween the focal point and the center of curvature
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Question 22
waec1990
Where will the image of the object OB shown in the diagram above be located after reflection from the mirror?
AAt F
BBeyond C
CBetween O and P
DBetween P and F
EBetween F and C
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Question 23
waec1990
A concave mirror of radius of curvature 20cm has a pin placed at 15cm from its pole. What will be the magnification of the image formed?
A4.00
B2.00
C1.33
D1.50
E0.25
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Question 24
waec1990
A stone is dropped into the middle of a pool of water. Which of the following statements is/are correct? I, Spherical waves are set up in the water. II. The water moves outwards to the sides of the pool. III. Energy is transmitted outwards from the centre of disturbance
AI only
BII only
CIII only
DI and III only
EII and III only.
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Question 25
waec1990
Which of the following is/are necessary for the production of interference with two wave trains? I. The sources must be close to each other. II The waves must have the same frequency. III. The waves must have the same amplitude. IV. The waves must travel with the speed of light.
AI, II and IV only
BI, II and III only
CI and II only
DII, III and IV only
El, III and IV only
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Question 26
waec1990
The diagram above represents part of a wave motion in air. If the wave travels with a speed of 300ms-1calculate the frequency of the wave.
A360Hz
B300Hz
C250Hz
D150Hz
E100Hz
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Question 27
waec1990
Which of the following is/are characteristics of sound? I Pitch II. Loudness III. Quality IV Noise
AI only
BII only
CI and II only
Dl, II and III only
EI, II, III and IV
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Question 28
waec1990
A tuning fork sounds louder when its stem is pressed against a table top than when held in air because
Aa larger mass of air is set vibrating by the table top
Bthe whole table vibrates in resonance
Cthe whole table has acquired a larger frequency
Dthe fork and table have the same frequency
Ethe amplitude of the vibrating fork is increased.
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Question 29
waec1990
A bat emits a sound wave at a speed of 1650.0ms-1 and receives the echoes 0.15s later. Calculate the distance of the bat from the reflector
A8.75m
B16.50m
C87.75m
D123.75m
E330.00m
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Question 30
waec1990
When the direction of vibration of the particles of a medium is perpendicular to the direction of travel of a wave the wave transmitted is known as
