A carregar...
|
Pressione e Mantenha para Arrastar |
|||
|
Clique aqui para fechar |
|||
Pergunta 1 Relatório
A man standing 510m away from a wall sounds a whistle. The echo from the wall reaches him 3s later. Calculate the velocity of sound in air.
Detalhes da Resposta
Pergunta 2 Relatório
A boy ran a distance of 200m in 24s. His average speed was 8.3ms-1. Which of the following is correct about the units in which the statements above are expressed?
Detalhes da Resposta
Pergunta 3 Relatório
Two 2.0Ω resistors can be combined circuit to give an overall resistance of
Detalhes da Resposta
Pergunta 4 Relatório
The specific heat of a substance in the solid state is C1; its specific beat in the liquid state is C2 and its latent heat of fusion is L. If a mass M of the substance is changed from the solid state at temperature T, to the liquid state, also at temperature T, the amount of heat required will be
Detalhes da Resposta
Pergunta 5 Relatório
The force exerted on a charged body in an electric field depends on
I. the charge on the body
II. the electric field intensity
III. the square of the mass of the body
Detalhes da Resposta
Pergunta 6 Relatório
A block of a substance X will sink in a liquid V but float liquid Z. Which of the following statements is NOT correct about the densities of the three substances?
Detalhes da Resposta
Pergunta 7 Relatório
To keep a lorry moving at a constant speed v, requires power p, from the engine. The force provided by the engine is
Detalhes da Resposta
Pergunta 8 Relatório
400g of cold water is added to 200g of water at 70°C. If they are properly mixed and the temperature of the mixture is 300°C. calculate the initial temperature of the cold water. (Neglect the heat absorbed by the container)
Detalhes da Resposta
Pergunta 9 Relatório
An element of nuclear number A and proton number Z emits an alpha particle from its nucleus. The nucleon number and the proton number of the new element formed are respectively
Detalhes da Resposta
Pergunta 11 Relatório
The half-life of a radioactive substance is 2 seconds. Calculate the decay constant.
Detalhes da Resposta
Pergunta 12 Relatório
A solid weights 5.0 N in air, 4.2 N in water and 4.4 N in liquid Y. Calculate the relative density of liquid Y.
Detalhes da Resposta
Pergunta 14 Relatório
An astronomical telescope which is being used to view a very distant object is said to be in normal adjustment if
Detalhes da Resposta
Pergunta 15 Relatório
The clinical thermometer differs from other mercury-in-glass thermometers because it has
I. a constriction
II. a wide range
III. a short range
IV. a narrow bore.
Which of the above are correct?
Detalhes da Resposta
Pergunta 16 Relatório
The smallest unit on the sleeve of a micrometer screw gauge is 0.5mm. There are fifty divisions on the thimble of the screw gauge.
What is the smallest length that can be measured with this instrument?
Detalhes da Resposta
Pergunta 17 Relatório
Which of the following is/are TRUE of nuclear fission?
I. A heavy nucleus is split into two nuclei of comparable masses
II. Two light nuclei are joined together to form a heavier nucleus
III. The total mass of the products is less than that of the reactants
Detalhes da Resposta
Pergunta 18 Relatório
A boy moving with a velocity of 3 ms-1 is brought to rest by a constant force after travelling 15m. Calculate the retardation.
Detalhes da Resposta
Pergunta 19 Relatório
A wave travels a distance of 20 cm in 3s. The distance between successive crests of the wave is 4cm. What is the frequency of the wave?
Detalhes da Resposta
Pergunta 20 Relatório
The image obtained on the screen of a pin-hole camera becomes less sharply defined when the
Detalhes da Resposta
Pergunta 21 Relatório
When a metal is heated to a high temperature, electrons are emitted from its surface. The process is known as
Detalhes da Resposta
Pergunta 22 Relatório
Two forces forming a couple are separated by a distance of 25cm. If one of the forces equals 40N, what is the moment of the couple?
Detalhes da Resposta
Pergunta 24 Relatório
The image formed by a converging lens of focal length is of a distance of 2f from the lens. Calculate the lateral magnification produced
Detalhes da Resposta
Pergunta 25 Relatório
If a positively charged glass-rod is used to charge an electroscope X by contact and an electroscope Y by induction, then
Detalhes da Resposta
Pergunta 26 Relatório
Which of the following is used in a nuclear reactor to slow down fast moving neutrons?
Detalhes da Resposta
Pergunta 27 Relatório
If the first position of resonance in a resonance tube is 18.0cm from the open end, the distance from the open end to the next position of resonance will be
Detalhes da Resposta
Pergunta 28 Relatório
The heat from a fire in a closed room reaches someone far away in the room, mainly by
Detalhes da Resposta
Pergunta 29 Relatório
A piece of stone weights 180 N in air and 150 N in a beaker containing 160 N of methylated spirit. What is the up thrust exerted on the stone?
Detalhes da Resposta
Pergunta 30 Relatório
An electric bell operated within an evacuated bell jar enables us to infer correctly that
Detalhes da Resposta
Pergunta 31 Relatório
A particle of charge q and mass m moving with a velocity v enters a uniform magnetic field B in the direction of the field. The force on the particle is
Detalhes da Resposta
Pergunta 32 Relatório
In a simple pendulum experiment, a boy observed that the times for 30 oscillations are 70.0s, 72.0s and 67.0s respectively. Calculate the mean period of oscillation of the pendulum.
Detalhes da Resposta
Pergunta 33 Relatório
The length of a side of a metallic cube at 20° C is 5.0cm. Given that the linear expansively of the metal is 4.0 × 10-5K-1, find the volume of the cube at 120° C
Detalhes da Resposta
Pergunta 34 Relatório
Which of the following is/areNOT affected by a magnetic field?
I. Alpha particle
II. Cathode rays
III. Neutrons
Detalhes da Resposta
Pergunta 35 Relatório
When electrical power is transmitted over long distances, the voltage is stepped up so that
Detalhes da Resposta
Pergunta 36 Relatório
When a lever is in equilibrium, under the action of two or more forces, the algebraic sum of the moments of the forces about the point of support is
Detalhes da Resposta
Pergunta 37 Relatório
A gas occupies a certain volume at 27°C. At what temperature will its volume be twice times the original volume assuming that its pressure remains constant?
Detalhes da Resposta
Pergunta 38 Relatório
Which of the following pairs of light rays shows the widest separation in the spectrum of white light?
Detalhes da Resposta
Pergunta 39 Relatório
Which of the following statements about evaporation and boiling is FALSE?
Detalhes da Resposta
Pergunta 41 Relatório
I. A scalar quantity has only magnitude
II. A scalar quantity has both magnitude and direction
III. A vector quantity has both magnitude and direction
IV. A vector quantity has only magnitude.
Which of the above statement is/are correct?
Detalhes da Resposta
Pergunta 42 Relatório
A radioactive substance has a half-life of 3 minutes. After 9 minutes, the count rate was observed to be 200. What was the count rate at zero time?
Detalhes da Resposta
Pergunta 43 Relatório
Calculate the peak voltage of a mains supply of r.ms. value 220V.
Detalhes da Resposta
Pergunta 44 Relatório
An electric iron rated 250 V has a coil of resistance 125Ω. What is the cost of using it for I hour at 10k per kWh?
Detalhes da Resposta
Pergunta 45 Relatório
A man at the back of a crowd watches a parade by holding a plane mirror just above his head. The parade passes 6 metres behinde his head and the mirror is 0.25m in front of the man. How far does the image in the mirror appear to be from the man?
Detalhes da Resposta
Pergunta 46 Relatório
What is the coefficient of static friction between a load of mass 2kg and a horizontal surface, if the limiting frictional force is 10N? (g = 10 ms-2)
Detalhes da Resposta
Gostaria de prosseguir com esta ação?