An object is placed 20.0cm in front of a converging lens of focal length 15.0cm. Calculate its image distance
A1.3cm
B8.6cm
C35.0cm
D60.0cm
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Question 13
waec2011
The speed of light in a certain medium is V while its speed in a vacuum is C. The absolute refractive index of the medium is
AC + V
B\(\frac{C}{V}\)
C\(\frac{V}{C}\)
DC - V
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Question 14
waec2011
Total internal reflection occurs in an optical prism when light rays
Atravel from the prism into an optically denser medium
Bare incident in the prism at an angle greater than the critical angle
Care incident normally in the prism
Dtravel from the prism to the air
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Question 15
waec2011
A ray undergoes a minimum deviation at 40o when it is incident on equilateral triangular glass prism. Calculate the refractive index of the prism
A1.48
B1.50
C1.53
D1.67
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Question 16
waec2011
The image formed by a convex mirror is always
Areal, erect and diminished
Breal, inverted and diminished
Cvirtual, inverted and diminished
Dvirtual, erect and diminshed
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Question 17
waec2011
Which of the following statements about the image formed by a plane mirror is not correct?
Ait is laterally inverted
Bit has unit magnifiation
Cit is formed by actual intersection of rays
Dits distance from the mirror is equal to that of the object from the mirror
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Question 18
waec2011
Ether produces a cooling effect when it is poured on the hand because it has
Alow conductivity
Bhigh conductivity
Chigh latent heat of vaporization
Dlow latent heat of vaporization
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Question 19
waec2011
A metal of mass 200g at a temperature of 100oC is placed in 100g of water at 25oC in a container of negligible heat capacity. If the final steady temperature is 30oC, calculate the specific heat capacity of the metal. [specific heat capacity of the water is 4200 Jkg-1 K-1]
A150 Jkg-1K-1
B300 Jkg-1K-1
C320 Jkg-1K-1
D1960 Jkg-1K-1
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Question 20
waec2011
A body is pulled over a distance of 500m by a force of 20N. If the power developed is o.4 kW, calculate the time interval during which the force is applied
A0.2s
B2.5s
C25.0s
D250.0s
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Question 21
waec2011
Which of the following assumptions is not valid for an ideal gas ?
Amolecules of a particular gas are identical
Bmolecules moves freely throughout the volume of the container
Cforce of attraction between molecules is negligible
Dmolecules move at constant speed between collisions
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Question 22
waec2011
Which of the following statements about anomalous expansion of water are correct? i. There is contraction between 0oC and 4oC. ii. There is expansion between 0oC and 100oC. iii. The volume is minimum at 4oC. iv. The volume is maximum at 4oC
Ai and ii only
Bii and iii only
Ci and iii only
Dii and iv only
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Question 23
waec2011
Which of the following equations shows how how the linear expansivity (\(\alpha\)) and the cubic expansivity (\(\gamma\)) of a material are related?
A\(\gamma = \alpha\)
B\(\gamma = 1 - \alpha\)
C\(\gamma = 2 \alpha\)
D\(\gamma = 3 \alpha\)
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Question 24
waec2011
A hypsometer is used for determining
Asteam point
Brelative humidity
Cice point
Drelative density
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Question 25
waec2011
The radius of a wheel is 30.0 cm and that of its axle is 6.0cm. Calculate the effort required to lift a load of 120.0N using this machine. Assuming 100% efficiency
A600.0N
B40.0N
C24.0N
D20.0N
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Question 26
waec2011
Which of the following statements correctly defines a simple machine? A device
Athat can produce electric current
Bwhich can only carry people from one place to another
Cwith which work can be done easily
Dwhich changes the state of rest or of uniform motion of an object
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Question 27
waec2011
A coin is pushed from the edge of a laboratory bench with a horizontal velocity of 15.0 ms-1. If the height of the bench from the floor is 1.5m, calculate the distance from the foot of the bench to the point of impact with the floor [g = 10ms-2]
A0.75m
B2.25m
C8.22m
D15.00m
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Question 28
waec2011
An object of mass 5.0 kg moves with a velocity of 10ms-1. Calculate its momentum.
A50.0 kgms-1
B15.0 kgms-1
C2.0 kgms-1
D0.5 kgms-1
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Question 29
waec2011
Two simple pendulum A and B of equal lengths and of masses 5g and 20g respectively are located in the same environment. The periods TA and TB of their respective oscillations are related by the equations
ATA = 4TB
BTA = \(\frac{1}{4} T_B\)
CTA = TB
DTA = 5TB
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Question 30
waec2011
A body of mass 120g placed at the 10cm mark on a uniform metre rule makes the rule settle horizontally on a fulcrum places at 35cm mark. Calculate the mass of the rule
