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Pergunta 1 Relatório
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]
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Pergunta 2 Relatório
When a light-weight body and a massive body are acted upon by the same force for the same period of time, the
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Pergunta 3 Relatório
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
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Pergunta 4 Relatório
Increasing the frequency of a sound wave produces a sound with
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Pergunta 5 Relatório
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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Pergunta 6 Relatório
Two objects, A and B, accelerate from rest at uniform rates. B accelerates twice as much as Compared to A, B travels
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Pergunta 7 Relatório
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]
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Pergunta 8 Relatório
The process of producing electric current by a changing magnetic field is referred to as
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Pergunta 9 Relatório
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
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Pergunta 10 Relatório
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.
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Pergunta 11 Relatório
A charge of 10 C is transferred across a potential difference of 220 V. Determine the work done.
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Pergunta 12 Relatório
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?
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Pergunta 13 Relatório
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
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Pergunta 14 Relatório
What is the name given to the force of attraction between the nucleons in the nucleus of an atom?
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Pergunta 15 Relatório
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
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Pergunta 16 Relatório
Which of the following equations is not a correct mirror formula? [The symbols have their usual meanings]
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Pergunta 17 Relatório
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)
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Pergunta 18 Relatório
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?
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Pergunta 20 Relatório
The purpose of commutators in a direct current motor is to
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Pergunta 21 Relatório
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]
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Pergunta 22 Relatório
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.
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Pergunta 23 Relatório
Which of the following statements about a ferromagnetic material is correct? It
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Pergunta 24 Relatório
The colours of the visible light region of the electromagnetic spectrum that have the shortest and longest wavelengths respectively are
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Pergunta 25 Relatório
The following statements are advantages of a solid dielectric material between the plates of a capacitor except that
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Pergunta 26 Relatório
Which of the following devices is associated with alternating currents only?
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Pergunta 27 Relatório
Which of the following statements about the properties of the electric field produced by charged parallel plates is not correct?
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Pergunta 28 Relatório
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
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Pergunta 29 Relatório
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
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Pergunta 30 Relatório
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?
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Pergunta 33 Relatório
The type of mirror used by dentists to inspect the teeth of patients is a
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Pergunta 34 Relatório
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
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Pergunta 35 Relatório
A direct current cannot pass through a parallel plate capacitor because
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Pergunta 36 Relatório
Which part of the human eye performs the same function as the diaphragm in a lens camera?
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Pergunta 37 Relatório
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.
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Pergunta 38 Relatório
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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Pergunta 39 Relatório
In a controlled thermal fission reactor, the use of control rods will not affect the
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Pergunta 40 Relatório
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
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Pergunta 41 Relatório
The ratio of maximum range to maximum height of a projectile is 4. Determine the angle of projection.
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Pergunta 42 Relatório
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.
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Pergunta 43 Relatório
The property of a body that determines the direction of heat flow when the body is in contact with another body is the
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Pergunta 44 Relatório
The conclusive test for magnetism in a steel bar suspended horizontally at its midpoint is when the bar
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Pergunta 45 Relatório
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?
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Pergunta 46 Relatório
Which of the following devices is used to compare the relative magnitudes of charges on two given bodies?
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Pergunta 47 Relatório
The most appropriate value of fuse for a kettle rated 220 V, 1.06 kW is
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Pergunta 48 Relatório
The diagram above illustrates a velocity-time graph. Determine the distance between X and Y.
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Pergunta 49 Relatório
Two objects, A and B, accelerate from rest at uniform rates. B accelerates twice as much as Compared to A, B travels
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Pergunta 50 Relatório
When an electron jumps directly from an orbit of n = 4 to n = 2,
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