WAEC - Physics (2023)

1
Which of the following statements about the properties of the electric field produced by charged parallel plates is not correct?
Răspuns
(C)
The magnitude of the electric field strength at any point between the plates is directly proportional to the magnitude of the charge on each plate.
2

The diagram above illustrates a mode of vibration of a wire of length 125 cm. The speed of the waves along the wire is 120 ms-1. Use the diagram to answer questions 2 and 3. Determine the wavelength of the waves.

Răspuns
(D)
0.50m
3

The diagram above illustrates a mode of vibration of a wire of length 125 cm. The speed of the waves along the wire is 120 ms-1. Use the diagram to answer questions 2 and 3.
Determine the frequency of the waves
Răspuns
(A)
240Hz
4

Which of the following diagrams correctly illustrates the mode of oscillation of air in a tube for the first overtone?

( The diagrams above are meant to help you in answering this question)

Răspuns
(B)
B
5
The process of producing electric current by a changing magnetic field is referred to as
Răspuns
(B)
electromagnetic induction
6
In a controlled thermal fission reactor, the use of control rods will not affect the
Răspuns
(C)
speed of the neutrons released on fission.
7
A body starts with an initial velocity of 20 m/s and moves with a uniform acceleration, a, for 15 seconds. Which of the following equations represents the distance, S, traveled?
Răspuns
(B)
300 + \(\frac{225a}{2}\)
8
In a mass spectrometer, an ion of charge, q, and mass, m, moving in a path of radius, r, in a field of flux density, B, has a speed of
Răspuns
(A)
\(\frac{qBr}{m}\)
9
Increasing the frequency of a sound wave produces a sound with
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(A)
higher pitch
10
A planet has mass, M, and radius R, If the universal gravitational constant is G, what is the expression for the escape velocity of an object on the planet?
Răspuns
(B)
\(\frac{\sqrt{2GM}}{R}\)
11
An atom in an excited state is one whose
Răspuns
(D)
electrons have moved to a higher energy level.
12
The most appropriate value of fuse for a kettle rated 220 V, 1.06 kW is
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(C)
5A
13
A 100 kg device is pulled up a plane inclined at 30° to the horizontal with a force of 1000 N. If the coefficient of friction between the device and the surface is 0.25, determine the total force opposing the motion.
[ g = 10 ms-2]
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(D)
716.5N
14
A solenoid is constructed by winding an insulated copper on a long test tube. A constant direct current is passed through the solenoid. Which of the following actions will not increase the strength of the magnetic field of the solenoid? Inserting a
Răspuns
(C)
Brass rod in the test tube
15
The following statements are advantages of a solid dielectric material between the plates of a capacitor except that
Răspuns
(B)
it increases the electrical conduction of the capacitor.
16
Which of the following devices is used to compare the relative magnitudes of charges on two given bodies?
Răspuns
(C)
Gold Leaf Electroscope
17
The instrument used to measure relative humidity is a
Răspuns
(A)
Hygrometer
18
A ball of mass 0.8 kg is dropped from a height, H. Just before hitting the ground, its velocity is 5.0 m/s. Determine H.
[g = 10 ms-2]
Răspuns
(A)
1.25m
19
The following statements are observations made about a towing vehicle and a bus that is being towed
I. The force exerted on the bus by the towing vehicle is of the same magnitude as the force that the bus exerts on the road.
II. The force exerted on the bus by the towing vehicle is of the same magnitude as the force exerted on the towing vehicle by the bus.
III. The towing vehicle exerts a force on the bus greater than the force exerted by the bus on the towing vehicle.
IV. The towing vehicle exerts a force on the bus that is the same as the force the road exerts on the towing vehicle.
Which of the following statements is/are correct?
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(B)
II only
20
Which of the following statements about a ferromagnetic material is correct? It
Răspuns
(A)
has a high susceptibility.
21
The type of mirror used by dentists to inspect the teeth of patients is a
Răspuns
(C)
concave mirror
22
In an RLC series circuit at resonance, the voltages across the resistor and the inductor are 30 V and 40 V respectively. Determine the voltage across the capacitor.
Răspuns
(D)
40V
23

The diagram above illustrates a velocity-time graph. Determine the distance between X and Y.
Răspuns
(B)
160.0m
24
A sound of frequency 512 Hz reaches a listener 100 m away. If the sound travels in air at s.t.p., what is its wavelength?
[speed of sound in air = 331 m/s]
Răspuns
(B)
0,646m
25
A charge of 10 C is transferred across a potential difference of 220 V. Determine the work done.
Răspuns
(B)
2200J
26
The ratio of maximum range to maximum height of a projectile is 4. Determine the angle of projection.
Răspuns
(C)
\(45^0\)
27
The range of wavelengths of the infrared waves in an electromagnetic spectrum is \(10^{-3}\) m to \(10^{-6}\)m. The wavelength of the radiation is
Răspuns
(A)
longer than \(10^{-6} m\).
28
An electron moves from an energy level of -8.6 eV to another level of -3.5 eV. Determine the frequency of the absorbed radiation. [1 eV = 1.6 × \(10^{19}\) J, h = 6.6 × \(10^{34}\) Js]
Răspuns
(D)
\( 1.24 \times 10^{15}\)Hz
29
A liquid is left in an open dish. After several days, there is less liquid in the dish. Which of the following statements explains this observation? The
Răspuns
(A)
most energetic molecules leave the surface and escape into the air.
30
The specific latent heat of vapourization of lead is 8.7 × \(10^5 Jkg_1\). This means that 8.7 × \(10^5\) J of thermal energy is required to change
Răspuns
(B)
1 kg of molten lead to vapour at constant temperature and pressure.
31
A car, P, with a velocity of 30 m/s is traveling in the same direction as a car, Q, with a velocity of 20 m/s. The velocity of P relative to Q is
Răspuns
(D)
\(10ms^1\)
32
When a light-weight body and a massive body are acted upon by the same force for the same period of time, the
Răspuns
(D)
momenta of both bodies remain the same.
33
A cell of emf 2 V has an internal resistance of 0.5 Ω. A current of 0.4 A passes through an external resistor, P. Determine the resistance of P.
Răspuns
(A)
4.5Ω
34

The diagram above illustrates a hot metal suspended at the centre of a closed uniform box. Thermometers E, F, G and H are placed in contact with four sides of the box. Which of the thermometers would register the highest temperature?
Răspuns
(D)
E
35
A direct current cannot pass through a parallel plate capacitor because
Răspuns
(B)
the dielectric between the plates is non-conducting.
36
The sagging of overhead electrical wires is caused by
Răspuns
(D)
Linear expansion
37
The property of a body that determines the direction of heat flow when the body is in contact with another body is the
Răspuns
(D)
Temperature
38
The colours of the visible light region of the electromagnetic spectrum that have the shortest and longest wavelengths respectively are
Răspuns
(C)
violet and red.
39
A ball, P, is released from the roof of a building at the same time as another ball, Q, is thrown vertically upward from the base of the building. Which of the following statements is correct?
Răspuns
(C)
The acceleration of P is equal to that of Q and both are in the same direction.
40
A lead bullet of mass 0.05 kg is fired with a speed of 200 m/s into a lead block of mass 0.95 kg at rest. Given that the lead block moves after the impact, determine its kinetic energy.
Răspuns
(C)
50J
41
In the Rutherford scattering experiment, a beam of alpha particles was fired at a thin gold film and few of the particles were deflected considerably. This shows that the nucleus of an atom
Răspuns
(A)
is positively charged and is concentrated in a tiny volume
42
What is the name given to the force of attraction between the nucleons in the nucleus of an atom?
Răspuns
(D)
Nuclear force.
43
When an electron jumps directly from an orbit of n = 4 to n = 2,
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(B)
a photon is emitted
44
Two objects, A and B, accelerate from rest at uniform rates. B accelerates twice as much as Compared to A, B travels
Răspuns
(C)
two times as far
45
Two objects, A and B, accelerate from rest at uniform rates. B accelerates twice as much as Compared to A, B travels
Răspuns
(C)
two times as far.