WAEC - Physics (2015)

1
Which of the following statements about mass and weight are correct? i. Weight is the force of gravity on a body. ii. The mass of a body is the quantity of matter in the body. iii. The weight of a body is greatest at the equator. iv. The mass of a body is greatest at the poles
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(A)
i and ii only
2
Materials that can be stretched and still return to their original forms when the stresses are removed are said be
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(A)
elastic
3
Which of the following units is derived?
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(D)
N
4
The barometric reading at a place is 73.5m Hg. Calculate the pressure at a point 30m below the surface of water contained in a reservoir at the place. [g = 10ms\(^{-2}\), density of mercury = 1.2 x 10\(^4\)kg m\(^{-3}\), density of water = 1.0 x 10\(^3\)m\(^{-3}\)]
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(B)
3.0 x 10 ⁵ Nm^-2
5
An object floats in a fluid when it displaces it's
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(C)
weith of fluid in which it foats
6
The resultant force in a couple is
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(A)
zero
7
The slope of a straight-line velocity-time graph represents
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(A)
uniform acceleration
8
A body is projected with an initial velocity U at an angle O to the horizontal. The time taken by it to reach its maximum height is given by the expression
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(C)
\(\frac{u \text{sin}\theta}{g}\)
9
Which of the following statements describes a body in a stable equilibrium correctly?
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(D)
ball in the middle of a nemispherical bowl
10
In a school compound a girl walks 40km due east from the laboratory to the staff room to submit her report. Then she returns and walks 30m due north to her classroom. Determine the magnitude of her displacement from the10m laboratory
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(C)
50m
11
Two strings each inclined at an angle 30o to the horizontal are used to hold a bucket of water weighing 20N. Calculate the tension i n each string.
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(B)
20N
12
A bullet fired vertically upwards reaches a height of 500m. Neglecting air resistance, calculate the magnitude of the initial velocity of the bullet. [g = 10ms^-2]
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(B)
100.0ms^-1
13
A uniform bar AB is balanced on a knife-edge which is 60cm from B by a mass of 22g which hangs at C 10cm from A. Calculate the mass of the bar.
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(B)
66.0g
14
A body of mass 1000kg is released from a height of 10m above the ground. Determine its kinetic energy just before it strikes the ground .[g = 10ms^-2]
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(D)
10⁵J
15
The crackling noise produced by aluminum roofing sheets on a house during a hot sunny day is a result of
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(D)
expansion of the sheets
16
Water is unsuitable for use as a thermometric liquid because it
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(B)
has narrow temperature range
17
The diagram above illustrates a block ans tackle pulley system in which an effort E supports a load of 100.0N. If the efficiency of the machine is 75%, calculate the value of E
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(A)
22.2N
18
A quantity of hot water at 100^oC is added to 400g of water at 10^oC until the temperature of the mixture is 60^oC.

Calculate the mass of the hot water added. [Specific heat capacity of water =4200JKg^-1 K^-1]
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(D)
500g
19
A battery of emf 24V is connected to three resistor P, Q and R as illustrated in the diagram. Determine the voltage across the resistor Q
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(B)
10v
20
In an experiment in which a molten substance is allowed to cool, the cooling curve above was obtained. The temperature 60^oC is known as the
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(D)
melting point
21
In an experiment in which a molten substance is allowed to cool, the cooling curve above was obtained. The temperature 60^oC is known as the
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(D)
melting point
22
Which of the following concepts is a method of heat transfer that does not require a material medium?
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(B)
radiation
23
Which of the following units is the S.I. unit of heat capacity?
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(C)
JK^-1
24
The pressure applied to an enclosed fluid to one end id transmitted equally throughout the fluid and to the container walls. This statement is
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(C)
Pascal's principle Heisenberg's
25
The diagram given illustrates a wave form. Determine the speed of the wave
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(D)
10.0 ms^-1
26
What type of wave is emitted by a loud speaker?
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(B)
Longitudinal
27
An object is placed 15cm from a diverging lens of focal length 12cm. The image of the object formed by the lens in
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(B)
virtual and 6.67cm from the lens
28
A swimming pool is 2.1m deep. If it contains water of refractive index 1.3, calculate the apparent depth of pool
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(C)
1.6m
29
When an air column is set into vibrations, the distance between two consecutive nodes of the resultant wave is
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(B)
half of the wavelength
30
A girl standing some distance from the cliff claps her hands and hears the echo 0.8s later. calculate her distance from the cliff. [speed of sound in air = 320 ms^-1]
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(B)
128m
31
Red light travels faster than blue light when both of them pass through a glass prism because the
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(D)
blue light is more intense than the red light
32
An object is placed 20cm from a concave mirror of focal length 15cm. Calculate the linear magnification of the image formed
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(D)
3.0
33
All electromagnetic waves in a vacuum have the same
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(C)
speed
34
The diagram given illustrates two charged particles W and X. The charges on W and x are respectively
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(A)
negative; negative
35
An alternating current supply is connected to an electric lamp which lights with the same brightness as it does with direct current source emf 6v. The peak potential difference of the a.c supply is
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(C)
8.5v
36
An electric generator rated 12 kW, 2 kV distribute power through a cable of resistance 20\(\Omega\). Calculate the power loss in the cable.
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(C)
720 w
37
Which of the following statements is correct? When capacitors of different values are connected in series
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(A)
the same charge flows through them
38
Which of the following statements about a three-pin plug is/are correct. i. The brown wire is the live wire. ii. The fuse is connected to the live wire. iii. The earth wire is coloured blue
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(C)
i and ii only
39

The symbol illustrated above is that of a resistor?
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(D)
whose resistance is light dependent
40
A wire of cross-sectional area 0.60mm² has a restivity of 7.2 x 10^-7 \(\Omega\). Calculate the length of wire that will have a resistance of 3\(\Omega\).
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(B)
2.50m
41
A battery of emf 24V is connected to three resistor P, Q and R as illustrated in the given diagram. Determine the voltage across the resistor Q.
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(B)
10V
42
The mass of the earth is 6.0 x 10²⁴kg and that of the moon is 7.0 x 10²²kg. If the distance between them is 4.0 x 10⁸m, calculate the force of attraction between them. [G = 6.7 x 10^-11Nm²kg^-2]
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(D)
1.8 x 10²⁰N
43
The angle which the direction of the earth magnetic field makes with the horizontal at a palace is know as.
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(B)
angle of dip
44
What must be connected between the points P and Q to establish a steady current through the incomplete circuit diagram given?
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(C)
Cell
45
When current flows through a moving-coil galvanometer, the force exerted on the pointer depends on the: i. strength of the current. ii. magnetic field strength. iii. length of the coil. Which of the statement(s) above is/are correct?
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(C)
i and iii only